Instead of taking a risk at the border, you may want to consider asking for a UK visa.

If you get rejected at the border, this will mean lost money (the cost of the ticket and any other non-refundable reservations you may have made), a stain on your record, a lot of hassle and trouble (as you notice last time, it can be quite stressful when they start asking questions beyond the usual, so imagine if they actually say no).

Given that:

• You have a boyfriend in the UK
• You have already stayed about 3 months in the last 4 in the UK, if I understand your travel history
• The last time you entered the UK, you were given only a one-month Leave To Enter instead of the usual 6 months
• You may seem to be trying to circumvent UK immigration by using alternative means of entrance in the CTA

The chances you would be rejected are not negligible.

Getting a visa, even though not a guarantee that you will be allowed to enter the UK with one, would significantly reduce your chances of being rejected at the border (if you were truthful in your visa application).

Requesting a visa will give you more time to gather all the required evidence (and understand what they expect -- even from someone who would normally allowed to enter without a visa) and present your case in better conditions (with a lot less stress) than at the border.

You may also want to check if there aren't any types of visas that could be more adapted to your specific situation (it's unclear from your questions whether you are planning to spend a lot of time in the UK with your boyfriend or even intend to marry him). Weigh the pros and cons of the various types of visas carefully though.

As to the title of the question, no, being a girl travelling alone should not make much of a difference, if at all. It's more likely it's your travel history which is the issue.

Instead of taking a risk at the border, you may want to consider asking for a UK visa.

If you get rejected at the border, this will mean lost money (the cost of the ticket and any other non-refundable reservations you may have made), a stain on your record, a lot of hassle and trouble (as you noticed last time, it can be quite stressful when they start asking questions beyond the usual, so imagine if they actually say "no", put you in a holding room — which in some places in more of a cell than a room, and send you on the first flight back home).

Given that:

• You have a boyfriend in the UK
• You have already stayed about 3 months in the last 4 in the UK, if I understand your travel history
• The last time you entered the UK, you were given only a one-month Leave To Enter instead of the usual 6 months
• You may seem to be trying to circumvent UK immigration by using alternative means of entrance in the CTA

The chances you would be rejected are not negligible.

Getting a visa, even though not a guarantee that you will be allowed to enter the UK with one, would significantly reduce your chances of being rejected at the border (if you were truthful in your visa application).

Requesting a visa will give you more time to gather all the required evidence (and understand what they expect — even from someone who would normally allowed to enter without a visa) and present your case in better conditions (with a lot less stress) than at the border.

You may also want to check if there aren't any types of visas that could be more adapted to your specific situation (it's unclear from your questions whether you are planning to spend a lot of time in the UK with your boyfriend or even intend to marry him). Weigh the pros and cons of the various types of visas carefully though.

As to the title of the question, no, being a girl travelling alone should not make much of a difference, if at all. It's more likely it's your travel history which is the issue.

Instead of taking a risk at the border, you may want to consider asking for a UK visa.

If you get rejected at the border, this will mean lost money (the cost of the ticket and any other non-refundable reservations you may have made), a stain on your record, a lot of hassle and trouble (as you notice last time, it can be quite stressful when they start asking questions beyond the usual, so imagine if they actually say no).

Given that:

• You have a boyfriend in the UK
• You have already stayed about 3 months in the last 4 in the UK, if I understand your travel history
• The last time you entered the UK, you were given only a one-month Leave To Enter instead of the usual 6 months
• You may seem to be trying to circumvent UK immigration by using alternative means of entrance in the CTA

The chances you would be rejected are not negligible.

Getting a visa, even though not a guarantee that you will be allowed to enter the UK with one, would significantly reduce your chances of being rejected at the border (if you were truthful in your visa application).

Requesting a visa will give you more time to gather all the required evidence (and understand what they expect -- even from someone who would normally allowed to enter without a visa) and present your case in better conditions (with a lot less stress) than at the border.

You may also want to check if there aren't any types of visas that could be more adapted to your specific situation (it's unclear from your questions whether you are planning to spend a lot of time in the UK with your boyfriend or even intend to marry him). Weigh the pros and cons of the various types of visas carefully though.

Instead of taking a risk at the border, you may want to consider asking for a UK visa.

If you get rejected at the border, this will mean lost money (the cost of the ticket and any other non-refundable reservations you may have made), a stain on your record, a lot of hassle and trouble (as you notice last time, it can be quite stressful when they start asking questions beyond the usual, so imagine if they actually say no).

Given that:

• You have a boyfriend in the UK
• You have already stayed about 3 months in the last 4 in the UK, if I understand your travel history
• The last time you entered the UK, you were given only a one-month Leave To Enter instead of the usual 6 months
• You may seem to be trying to circumvent UK immigration by using alternative means of entrance in the CTA

The chances you would be rejected are not negligible.

Getting a visa, even though not a guarantee that you will be allowed to enter the UK with one, would significantly reduce your chances of being rejected at the border (if you were truthful in your visa application).

Requesting a visa will give you more time to gather all the required evidence (and understand what they expect -- even from someone who would normally allowed to enter without a visa) and present your case in better conditions (with a lot less stress) than at the border.

You may also want to check if there aren't any types of visas that could be more adapted to your specific situation (it's unclear from your questions whether you are planning to spend a lot of time in the UK with your boyfriend or even intend to marry him). Weigh the pros and cons of the various types of visas carefully though.

As to the title of the question, no, being a girl travelling alone should not make much of a difference, if at all. It's more likely it's your travel history which is the issue.