Why is everyone pressuring me to get married. I'm 30 years old for goodness sake?

It's not like i'm 40. 30 is still young. I've been with my boyfriend since i was 16 and he was 19. So there's a 3 year age gap between us. naturally we've had our ups and downs, including a few breakups here and there. At first he didn't want to commit to a relatonship, took him about two years to ask me to be his girlfriend because he still wanted a 'friends with benefits' thing and i wasn't down for that. But now we're stronger than ever and i feel like we can conquer anything. However, that DOESN'T mean i want to get married a.s.a.p. I don't feel like i HAVE to get married right this moment. I don't know why everyone's rushing me. We already have an 11 month old daughter so it's not like my eggs are dying out either. He was going to propose but i told him i wasnt ready at this moment. I love him with all my heart, i'm IN love with him. My sister who is 24 is like " why don't you want to get married? mabye he's not the 'the one'? . He is the one , i'm sure of it.