My period is so weird

Hi ladies, before i share my short story.. of COURSE ill be visiting a doctors office soon. I just want to know if there are any ladies that have gone through what ive gone through?

Soo last time i got my period was late march, early april. I have not been sexually active since feb, took many pregnancy tests and nothing.. april came around, no period.. may came around, no period, june came, and NO period.. i had protected(condom) sex with someone on june 30th, and then i believe we ended up taking it off after he finished.. so now its july 24th and i got my period on the 22nd but it’s so weird to me because all the blood coming out is brown, as well as brown blood clots. I know its old blood. I just wanna know if anyone has had the same situation? My friend suggested i take a pregnancy test but i highly doubt i could be pregnant. I guess having sex triggered my period? I dont know, any thoughts an opinions?