Can baby teeth grow and not come in pairs?

Haha yes this is very common lah, don't worry! Baby teeth don't always come in perfect pairs at the same time, some babies get one tooth first then the other side comes a few weeks later, every baby is different one. As long as by around 12-18 months your baby has started getting some teeth already then generally no cause for concern, but if by 18 months still no teeth at all then best to check with your PD just to be sure!