What else could cause pregnancy symptoms?!

For about two months now I have had nausea in the morning and night, dizziness, headaches, my breasts have grown almost a cup size, my nipples have gotten larger and darker around the outside, my cm has not stopped after ovulation as normal, I even have felt slight pressure above my pubic bone for two months regardless of what time it is (similar to ovulation pain) and every afternoon I hit a wall and get extremely tired. Last month 4 days before my period I experienced VERY heavy bleeding with clotting and cramps so badly I couldn't stand up. The dr said it may have been a miscarriage but we wont know for sure (Although Im pretty sure it was). The symptoms stopped for a little while, but they picked up again and were more extreme. I thought for sure I was pg but had a negative blood test. i also have recently gotten my period (it was two and a half days long). In my family it is common to bleed as though it is your period and test negative for up to three months. Im pretty worried because what if im not pregnant something is very wrong. What else causes pregnancy symptoms like mine?