Could I be pregnant?

I have a 5 month old son that has been exclusively fed with my breastmilk. I haven't had my first period yet. Husband and I have had unprotected sex a handful of times because we don't mind if we get pregnant again but I've heard it's very unlikely to happen since breastfeeding is almost as good as birth control.

I have been extra moody lately and craving ice cream. During my first pregnancy, I craved ice cream like crazy but didn't have the mood swings.

Could I be pregnant again???