Breastfeeding is *not* contraceptive, so if you didn’t use other forms of contraceptive you could be pregnant.
Do a test, but I heard it’s common not to ovulate for the first cycle
Breastfeeding can cause irregularity. It's normal for things to be messed up for a couple of years as that's how long it takes for the hormones to balance.
You most certainly *could* be pregnant. So I would test if you aren’t sure. However, my period postpartum has been coming every 6 weeks due to breastfeeding so it most certainly can be irregular as well. When in doubt, test.