Ttc with no luck! Help Please!

I'm 17 & bf 19 been together 5 Years when we first got together we used protection then after a year we stopped using protection and I never got pregnant and now we want a baby so bad! Idk what to do I have gotten my periods regular when I had ordered a bottle of feritlaid and took prenatal vitamins for a month cause they have been irregular I'm think on trying some vitamins for me and him what are the best vitamins we can get? & we have intercourse every night and multiple times during the day so I know it's not that and I have never been on birth control and I used to get my periods every 3 months but now they have been regular for awhile. If anyone has any helpful advise I would appreciate it thanks!😞