Please read and help me! ):

Okay so I've been really constipated for the past few weeks and I found out I'm pregnant 6/7 weeks now, and that I am now anemic. But lastnight when I got home there was brown spotting in my underwear, and when I wiped, there was pink discharge. Then this morning before I peed, like three drops of blood fell in the toilet, so I wiped (before I peed) and there was nothing! I'm so nervous, because of the constipation I don't know if I'm having "cramps" or just an upset tummy from not being able to go potty /: 
So I went ahead and made an appointment just in case and she did an external and internal examination then did a transvaginal ultrasound. She couldn't find the baby's pregnancy sac ): my HCG level is at 24.5 and i need to go back on Monday to check if it goes up or down. When I got home I started bleeding, the blood is red/dark red. I sat on the toilet and a bunch of blood came out. Then again a few minutes later, then the last time it was less but still red. And I'm having those "cramps"?? I'm crying so much because I don't want to believe that I'm having a misscarrige, anyone else had a similar situation? I don't know what's going on ):