You can check your cervix!
The best method is to use a pregnancy test but I assume that since you are asking this question you want to know if there are other methods. Well, one would be to check your cervix. If it is really low and hard (as if you were touching the tip of your nose) it's because you are about to have your period. If it is higher up and soft (like your lips) it could be a possibility that you are pregnant. You don't sound like you're ready for another child at the moment lol but children can be a wonderful blessing:) Either way, good luck and it can also be high up and soft if you're ovulating. There are also YouTube videos describing it in better depth.
Take a home pregnency test....
Take a home pregnency test....