Could I Be Pregant Or Is It the Pill Causing This?

I'm 19years old and started having sex with my boyfriend 3months ago. We were stupid for the first month by not using contraception. I went to the doctors and had a pregnancy test and it came out negative. But I was told that I could get pregnant because I have sex 3 times over the last 3 days before having the test and was giving the morning after pill. But being stupid again I didn't go and get the morning after pill therefore not taking it. I also started taking the contraceptive pill at this time. 2 months on now and I'm starting to suspect I may be pregnant. My boobs are always really sore to touch and lumpy and have gone up at least one cup size causing me backache as I was already a DD. I have just started getting bad headaches over the last few days. I'm constantly tired and dehydrated. I also started throwing up after eating certain things and I've gone right off alcohol when I used to fancy it, 3 glasses the other night made me throw up for 3hours after. And someone mentioned a week ago I looked like I was in the early stages of pregnany as my usually slim stomach bulged out to one side when I was leaning on something, but not in a flabby way, more pot belly like. After all this it may look like I defo am pregnant but the one thing is I have bled heavily twice now with constant spotting in between except for one week where I had nothing. But after reading you could bleed heavily while pregnant Im not so sure. Do you think its worth going for a test or could all this be down to the pill? I also keep getting very emotional, crying at nothing. If I could be pregnant it could be up to 2months and a week.