If I have been pregnant before does that mean I'm able to get pregnant again? Or do I need to be checked for infertility? My husband also has a child with someone else as well is he infertile?

Secondary infertility is quite common (meaning you become infertile after already having achieved pregnancy and/or had a child). You should still be checked.

Ask your OB for a "preconception appointment" and go from there. You'll sit down together and based on your history, they'll advise you on the next step.