TTC. Need some guidance

My husban fan do we're only together for 4 months before we "accidentally" got pregnant with our daughter. He didn't even cum inside of me (I know visually) he pulled out but put himself back in. 3 weeks late I found out I was pregnant. Now we are trying to conceive our second child an I can't get pregnant. I know that timing is everything but I can only have sex so much before my hoo-ha feels like it's going to fall off. Give me some advice please