Is my partner infertile?

Hey everyone

I am genuinely concerned that my partner is infertile. Since we've been together he's always made a joke saying "I think I can't have kids me" and when i ask why he says it's because he doesn't c*m very much... I said to him that there are obviously a lot of sperm that exist so not to worry

But now he's said it it's really got me thinking...

I have been pregnant twice in the past (pretty much straight away). This was with my ex partner. The first time we miscarried and the second time i had a termination. But while I've been with my current partner, i've been off of my copper coil for nearly 4 months now, and still nothing? It's honestly concerning me. I know it's still early days but i'm really worried and he doesn't seem too bothered. I've told him to go to the doctors but he just brushes it off..

Any ideas??