Confused!! Should I take a HPT??!! Please help!!

Lyssa • mother of a 6 yr old girl, 1 1/2 yr. old boy & a 3 1/2 month girl..
Im in my early 30's.. I always had my AF for 8 days, & always a regular cycle.. On July 27 I got my AF, then the day after it ended on the 4th of August.. The next day, I was spotting pink, continued a few days, then it was brown discharge..  That was for a week.. Then on Aug. 10th, I started  bleeding for 5 days, until the 16th.. We are TTC, now it's the 30th of Aug.. I dunno if I should get a HPT.. Bc I'm late.. Or do I go by Aug. 10th cycle??. N this past few days, I'm super nauseas!! Any advice, would be appreciated !!! Thank u...