Saying ,,i love you”

So i am with my boyfriend for 6 months now.I am 21 and he is 27.He told me he loves me on our 1 st month and I thought it was very early but i said it back because somehow i could feel this emotion too.Since then we have said it to each other but not so frequently.The last time he has said it was 2 weeks ago and he had to travel for work for a couple of days.Since then i told him once when we had sex and he said it back.But idk should i be worried that he stopped saying it first?Should inask something or?