Yep, most women break their hymen during exercise, tampon, or something else without even knowing. Unless you have a septate hymen (it has a thing string of extra tissue that creates two openings-- you'd know if you had one) then its unlikely he was able to tell just by looking.
But in any case, your hymen has nothing to do with virginity. You had sex, so you're not a virgin-- not like it really matters though, so don't stress about it