Pregnancy Test (Breastfeeding)

Hey Moms!

I'm Breastfeeding (and giving 1 x formula bottle per day). My period has not yet returned and baby is 4.5 months old. I had a very regular cycle before getting pregnant and got pregnant on our first month trying last year.

I am not yet on any birth control. My husband and I had unprotected sex about 3 weeks ago. We literally forgot the condom.

I know breastfeeding isn't a great form of birth control. When do I take a test just to make sure I'm not pregnant? Is it too soon to take it now?