Somebody, please read and answer! 17 and signs of pregnancy?

Okay, so I've read a lot of things off this site and it's been truly helpful but I have one problem.. I'm 17 and I've been with my boyfriend for 3 years and 2 months, I just turned 17 today and I've been on birth control and what not since 9th grade. I've only had sex with my boyfriend so there hasn't been 'other guys'. Anyways, since I've been on birth control, it's worked fairly well for me and we don't bother with condoms. He's cummed inside of me, and it hasn't led to pregnancy once. I've had scares, don't get me wrong but they all ended up to be late. I've had my period since I was 10 sadly and it has always been irregular. I was taken to an obgyn at the age of 10 and the obgyn just put me on pills(at the time I wasn't aware that I was on birth control). So as time went by my periods got better but were still a little off which is better than getting my period every two weeks. I visit the obgyn regularly and because my period is so heavy(it's kept me from going to school it was THAT heavy) my obgyn decided that with the regular birth control I've been on(and no it's not like seasonique or yaz) that I could get my period every 3 months safely. So I went with that plan, and I get my period every 3 months but I just recently had my wisdom teeth out and I was made aware while on the antibiotics my birth control would stop working, and I was smart with the information given but just the other day my friend had told me that the antibiotics basically defects your birth control that entire month regardless if you stop taking them. I was not made aware of that and I obviously had sex with my boyfriend and he cummed inside me. Now I'm terrified because lately I've had nonstop cramping pains in my stomach and bc I don't get my period every month I can't tell by missing my period. I also want to make everyone aware that I am on anti depressant medication and a stimulant but I visit my doctor every two weeks for that so it's not like I'm not under close watch because I am taking all of this medications for my ADHD and OCD. But I am curious to know if anyone really thinks there's a possibility I could be pregnant under all these circumstances.. I am not able to get a pregnancy test only because I wouldn't be able to do it without my mom knowing so it's really frustrating knowing I have to get an opinion rather than a test but I'm just curious. I've had lower abdomen pains, I'm sleepy and I've woken up plenty of times at like 3 in the morning feeling extremely nauseas to the point where I couldn't fall asleep. Please help, I'm open to anyone's opinion so speak freely I won't judge ! Thank you