Tampons after sex

I started my period this afternoon, and my boyfriend and I had sex pretty much an hour later, just in the moment. I went to put in a tampon after we finished, but I had a thought of maybe it wasn't a good idea to put a tampon in while I still had a lot of cum inside me. I used a pad instead.

But I'm just wondering if anyone else would be worried about this or should it be ok?