Could my period be thrown off please i need answers

Ashley

So I was suppose to start the 14th of this month I ended being 4 days late I tested on day 3 nothing went to health department day 4 negative I started the 19th I bled normal but brownish blood bright red first day then brown like it started to look like when I come off my other periods anyways I bled normal sat and Sunday but Sunday night I put a tampon in before bed Monday morning I wake up change it the tampon is dry nothing on it not a spot of nothing so later on in the day popped back up browinsh red I put a tampon in took it out barely nothing the tampon has brown blood at the top of of it not even filled just the top of the tampon brownish color now nothing only thing I noticed is I'm extremely hungry and I got headaches and before I even started bleeding I got these tough cramps and they stop and then come back never consistent and I definitely been constipated could I b pregnant when should I test again I never been late always start on time if not I go a day late n then start sometimes or a couple days early lately I been starting early..... I'm 28 never been pregnant