Is this normal

I finally hit 6 weeks so me and SO decided to have sex for the first time after having the baby, is it normal for my vagina to kind of “burn” during and after? It definitely hurt to have sex again for the first time. But is the burning normal? It’s been about 15 minutes since we had sex and the burning is gone. Sign of an infection?

To Update Since Anonymous:

• I breastfeed

• We used spit because lube normally gives me an infection, I already felt super wet before that because of foreplay. Maybe it wasn’t wet enough?