Period

I'm a little confused! I was spotting for three days light brownish discharge and thought I was going to start my menstral period, but on the forth day it just stopped and I never had any heavy or medium period like I would normally. My periods are always on time maybe off by a day but I do start a normal 5-6 day flow. I've never had this happen to me and I'm wondering if I should take a pregnacy test?? My husband and I have been trying get pregnate for about 5 months.