Sex & Religion

Hi! So I'm a Muslim, I don't practice fully, however one of the things I've stuck to is "no sex before marriage". I've had previous relationships over the years and sex was never an issue, however I'm now 20 and still a virgin... I've just got into a new relationship and he says it's fine, that he doesn't mind but I feel like it's a bigger deal than I realise? Please help! -S x