Implantation bleeding or period

Good morning everyone,

I'm completely new here on the forum, and under the guise of "daring to ask," I've decided to create an account anyway.
I'm a 31-year-old Belgian, I have a beautiful 3-year-old son, and we've been trying for a second baby since December.
Last month didn't work out, and now I'm anxiously waiting to see if my period will start.
It's either Thursday or Saturday, I'm not sure, since I didn't really feel my ovulation this time. According to my app, it should have been Saturday the 2nd/3rd, but I had no real ovulation symptoms then. A few days before that, though, I had quite a lot of pain during sex (which I never normally have), so ovulation could have been then as well.

Now, since Sunday I've been having a little bit of brown discharge, not a lot, but also not enough for the whole day to stay dry... (sorry for the expressions). I've had very sore breasts for a good week now, and that's been a little less since yesterday. Otherwise, no real symptoms. So on Sunday I had brown discharge, with a bit of pink in the afternoon, then no more pink, just brown until now...
Does anyone recognize this? I'm really going crazy.
Last month I also had some brown discharge, but not for so long, and not as far in advance either.