Tips?

Well my partner and I have been together since age 12. We have two kids. One 8yr and one is 4years old. We were trying for our last one for awhile. It has been 5 months or more now and still no baby. Now all of a sudden my partner is no longer interested in having another :(

I on the other hand would have tons more lol I just love babies and my pregnancies thus far have been so easy! What should I do to get my partner on the same boat tho? I know I'm lucky and blessed now but I'd love to try for a girl ♡