Am I having a misscarrsige or just my period?

I had unprotected sex day before ovulation,, nd few days after period wasnt due till the 18th but came 3 days early which has been coming on time these past 5 months nd not early,, could I have been pregnant because I took a test a on the 14th one came out negative then other was positive but thats when I began cramping nd the next day I wss bleeding,, now today 4 dats into hsbing my early period im having really sharp pains not usually what I get when I have my period nd alot of blood clots are coming dwn,m my question is could I have been pregnant nd now experiencing a misscarrsige? Please help !!!!