Hello and Welcome to ‘Ask A Doctor’ service.
I have reviewed your query and here is my advice.
Short answer:
Pregnancy highly unlikely.
Detailed answer: When birth control methods are used appropriately, i.e. when they are used according to producers guidelines, then a pregnancy is almost unlikely (99.9% unlikely) even though you have unprotected sex.
Therefore, assuming that you have followed rigorously the guidelines for birth control usage, and taking into consideration that most of the time you and your boyfriend have protected sex and when not, he pulls out before he comes, I would reasonably think that you are not pregnant.
The issue of weight gain is not an indication of pregnancy in your case, since in some case the use of birth control pills could cause a mild weight gain due to increased fluid retention and/or change in appetite, even though today modern birth control methods use very low levels of hormones.
In case you are using an
estrogen based birth control method, then it is very likely that your weight gain is due to increased water retention and not fat.
If your birth control method is based on progestin than your weight gain is likely to be due to extra fat stored.
In case you are concerned about your weight gain then you have to talk to your gynecologist and decide about the option to change the birth control method in order to have a lesser impact on your weight.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Ervin Toçi