I’m not sure if he finished inside me

My boyfriend and I are trying for a baby I am 35 and he is 48. We was baby dancing the day I ovulated he said he came in me. But I didn’t feel any leakage but He stayed inside me for a few minutes and I laid down for 5 more minutes. Also because I was ovulating I guess my cervix was open. So my question is how do I know if he finished inside me if there wasn’t no sperm leaking out? I asked him if he came in me and he said yes