Fertility?

So, going to try to keep this short but I’ve never really been a very sexually actively person.

My last long term partner we only did stuff a handful of times in the years we were together.

That being said, I met someone that I really hit it off with, and we are quite active together.

He has stated he thinks he has fertility issues as he’s had two long term partners he’s tried to have children with and it never happened. (He is older than me by a bit so he’s had one more long term than me)

Reason I state this is because he likes to… we’ll say have me entirely, and I’m unsure if I should get the pill?

My period is supposed to be in about 10 days and idk if I should get the pill or just leave it. I also feel bad for thinking about taking it since he wants children so badly and it makes me feel like I would be ruining a possibility of that happening for him.

It’s sad idk when I ovulate, but I’m not really versed on that stuff. Never really been a reason to worry about it and this is the first person I’ve been like this with.

Are there home tests he could do to check his or my owns fertility?

I also don’t want to keep buying the pills if it is common occurrence, I have BC but I’m scared to take it because weight gain and headaches and feeling sick. I have thyroid issues and Endo PCOS stuff and my hormones are already crazy so I am worried to get on it even if it would help my monthlies and of course be handy if my partner keeps up with this stuff.

I thought the most fertile was about a week after monthly for 5 days but I’m not sure.

Anything helps!