I need some advice!

So let me just start from the beginning so you know exactly what I'm experiencing. It started about a month ago when my "period" came 9 days early & only lasted a total of 3 days. Usually my period starts on the 10th & lasts for 5 days.. I took HPT & they came back negative.. I just thought I took the test too early, but the next day I had an annual check up with my gyno & she did a blood test, which came back negative.. I'm still thinking it was too early to tell because my "period" wasn't supposed to come for another week. I just blew it off & waited until my next period came, which it came around the same time this month (9 days early), & Im on the second day of it, which is not enough to fill a tampon. Yesterday, it was pretty intense & I had cramps, when usually I cramp for the first two days & it's usually really heavy for 3 days, this time it's almost completely GONE & I'm on day 2.  It felt like a normal period yesterday, but today it feels like it's about to go away. 

im not sure if it helps to say my mom had a "period" with her first pregnancy & didn't even find out until around 4 months.. I took a hpt almost a week ago, but it was a cheep one from the dollar store & it came back neg. I'm just really confused of what is going on with my body & I can tell something doesn't feel "normal".  I just want to know if anyone else has experienced something like this.  I do have unprotected sex 3-4 times a week so that's why I'm thinking it could be a really weird pregnancy.. But then again I don't know because it's not very common.  Any thoughts or ideas? if I try talking to doctors they will think I'm crazy because it doesnt happen very often.. But I just want to know what's going on!