He is unsure if he has finished or not, but I didn't feel any liquid

I had unprotected sex with my bf...we didn't do enough because he was saying that he is feeling very much pleasure and he won't know if he will cum...after a little he told me to stop and he said that he maybe had already cummed and thats why he was feeling so much pleasure...btw i didnt felt pressured or warm inside and 2-3 minutes later where i wasnt turned on i putted finger but i didnt feltany liguid.He cummed or no? What should i do to know? So confused...