Someone please help!

I'm 18 and the last time I've had a NORMAL period was January 28th.. My next period came on Feb. 24th and it wasn't as heavy and it didn't last more than 3 days. I started getting bloated and I gained about 5 pounds. I look like I have a ball in my tummy. I was feeling sick to my stomach, even smells were making me feel sick. I had pains around my belly button and my back and sides. My breasts were getting sore and I have been feeling more tired then usual. Seeing as I got my period, even though it was late.. I thought I'd wait to see if I got my period the next month before taking a pregnancy test. My period this month was due on march 24th and it didn't come.. I took a home test on march 28th but it turned out negitive. I thought I had done it wrong or not enough urine was put on it. That night I started bleeding, but only a little bit. It wasn't heavy enough to say it was a period. It started off like the end of a period would. The next day I went in to the doctors for a blood test and the test came out negative.Yesterday the bleeding was clumpier and darker and today, so far, I haven't been bleeding much at all.. I still feel bloated and all of that.. DO you think I could have been pregnant and had a miscarriage and by the time I got the test done it was too late to find out????