Have tummy pain and feel it getting bigger, I am worried. Why is this?

okay so im 18 and i live with my boyfirend, we have sex almost 3-4 times a week everytime he finishes he cums in me. about a month ago i noticed my tummy has beengetting bigger and i dont even push it out. I have been eating more then usual. And recently my tummy has been having this weirdpain when hima nd i have sex. and my boobs have started hurting aswell,butthis is weird to say but he did suck on them a few days ago and idk if its because of that,that they are or what. Also i was in decent shape because im a dancer and now when i walk up my stairs to get to our apartment i get really tires fast, or even walking for a period of time i get tired. I have also been having trouble falling asleep at night and when i do finally fall asleep i sleep in sleep in late from what people say it is but im not really sleeping for long, and yes i have been going to the bathroom more often. Somehtings that i havet been abel to really tell the smell of i am starting to smell and it groses me out. like "Pam" that non stick stuff i never could smell it but lately i can smell it everytime i use it or my boyfriend does, and i want to throw up. and my clothes that were to big now fit me and some of mt newer clothes are starting to fit me uncomfortablely. Lastly, i have been having head aces that dont go away no matter what i do. Someone please help me!!:/ I dont mind if im pregnate, we would be happy. but we just want some answers. so please help