early "period" enlarged veiny breasts, pregnant?

hello! I am a 23 year old female. My periods are fairly regular with some bloating, slight breast tenderness and god awful cramps. My partner and I had unprotected sex in the beginning of July, and one time when I believe it was my ovulation day according to my calendar. My breasts grew 2-3 cup sizes, I was a C before and am now on the fence of DDD/E,I went in for several bra fittings because none of my bras are fitting me. I have never ever experienced my breasts GROWING before a period, also I have never in my life had the veins so visible on my breasts and chest area...my partner actually pointed this out to me. My nipples are also very sensitive and hurt when touched or brushed up against. I am also not fitting into many of my jeans, although it doesnt seem like I gained a lot of weight. Ive been feeling nauscious, however the nausea for me isnt neccessarily a sign of pregnancy because I do experience it regularly. I got my "period" today, it's 4-5 days early and it's also a bit unusual because it's lighter but I still require a pad. I took a HPT a few days ago and it tested negative. My breast enlargement and the veins are troubling, can I be pregnant? I do know some girls who have gotten pregnant and still had their periods in the beginning...thank you for your responses, I greatly appreciate it! If i am pregnant, this would be my first pregnancy