Ugh. Confused

So I’d just like to state that I am a single mother to a 16 month old BUT with that being said I’m thoroughly confused right now. Here’s the story:

I started talking to this guy over a month ago (we have history but never actually dated, just talked when I was pregnant with my daughter) and we decided to go out to see a movie on like a date and we hooked up, I’m on birth control but he didn’t wear a condom.

I got my period on the 28th of December and it lasted until the 1st, we hooked up on the 2nd.

I am now experiencing some light and I mean very light bleeding but I don’t have any PMS symptoms except a little light cramping and a headache (which comes and goes) I’m pretty sure it might be implantation bleeding but I didn’t experience that with my first pregnancy.

Anybody know wtf is going on ? I also don’t know when I should take a test because I waited for a bit with my daughter but I knew something wasn’t right with my body at that point. Thanks I’m advance for the help in case I forget to say it.