Anyone with similar situation ?

I don’t have regular periods so I never really know when I’m ovulating. I haven’t used ovulation tests yet it’s my first month trying. I got off my period on the 24th and had sex on the 28th, 30th, 1st, 2nd, and 5th. With my last pregnancy I had gotten off my period on the 1st of January and had a positive pregnancy test on the 23rd of January. So I’d Imagine I ovulate pretty close after my period ends. Well today I have bleeding and I am not supposed to have my period until the end of the month. I usually get it between the 20th-25th of every month. Is this implantation bleeding? Or maybe something else? Any advice really helps!