I didn't know where to post this, just wanted to talk to someone about my concerns.

I am not currently in any form of a relationship, and think i may be pregnant but am not sure i want to know...
I am 20 and i am currently studying at uni full time.
I can't actually remember when my last period was because i am on the pill and have skipped a few in a row!! I decided not to skip this time, and am due probably today or tomorrow.
The things that made me think maybe I'm pregnant is putting on weight, mainly in my stomach and breasts. Extreme fatigue. Sore ribs, lower back pain if i stand for too long, increased appetite and increased thirst, constant cravings for peanut butter lol and i have noticed some feelings in my stomach that is like twitching. I get it at all different times of the day, sometimes just like one little bump and other times it feels like a twitch.
If this is the case I'm guessing i must already be a fair way along! Although my stomach was always larger (extra fat) than it should be so i can't tell from looking.
My plan is to wait and see if i get my period and then if not i guess a test and a dr's appointment will be next...
I'm scared that if i am pregnant the baby is going to have problems, as being a uni student my diet is not the greatest and i have been out to the pubs on weekends drinking alcohol...