Should I take a test....

Okay so last month my fiance and I had a few incidents and I was worried I could be pregnant my periods usually last between 6 and 7 days and I was supposed to start my period on the 2nd and I actually got it on the 31st and it's only February 3rd and my period is already over... with my son I had my period threw my entire pregnancy and with my last pregnancy I had it up until I was told I was pregnant i was in the hospital cause I was really sick from malnutrition and dehydration so they did a bunch of blood work including a pregnancy test and a half hour after I got my blood drawn my period just stopped I was 3 weeks along by that point... which according to my lmp (if I don't count this last one that lasted 3 days) January 5th I'm 4 weeks 1 day I took two tests already the first one was just because I hadn't taken one of the dropper tests before and I want to be sure I knew what I was doing it came back NEGITIVE and then I took another one because I kept feeling sick (which is what happened with my last pregnancy) it was positive so because I had one NEGITIVE and one positive I decided to take another it was NEGITIVE but I also know that false positives are like a one in a million Shot so should I call my obgyn and make an appointment to get blood work or just accept a 4 day period and be happy..... I'm not sure how to take this period I've never had a period that lasted less than 5 days