what am i doing wrong

my husband and I are ttc and he thinks that he's doing great because he came in me three times in the year and a half we've been together ...

idk what to do we have plenty of sex but the other night he asked me if he was even in I'm 21 he's 28 this should not be happening any other relationship I've had where I've been sexually active I've been told I'm very talented... he has no problem masturbating and it's causing me to start thinking it's something I'm doing