Pregnancy Crazed Issues

Okay!!!!! here we go. My last period was on Jan. 14th and ended on the 19th, I was supposed to start my next cycle on or around the 9th of Feb. but I have seen nothing. In between those dates I have had sex almost everyday and sometimes multiple times ( sorry i know that was probably TMI.) By the 17th of Feb. and still no signs of my cycle I began to believe that I had conceived. My cycles are normally regular and I come on my period every month like clock work. After waiting some time ( in denial of course) I finally decided to take my first hpt on the 27th, which came back positive. Well...... here is were trouble in paradise began. The following day after taking the test I began having some spotting and even passed what look like a piece of uterine lining when I went to use the bathroom. It has now been two days and I still have some brownish color bleeding which is fairly light and not heavy like my regular period. I also have some very mild cramping that was also happening before the bleeding occured. I am a little worried because I do not know what to think. Someone please help me cause my boyfriend is driving me crazy because he think that I may have miscarried. And I am stressing out simply because he is stressing out and it is driving me up the wall.