Burning?

Me and my husband haven't seen each other in like five months. He's finally here with me to stay for good and we just had sex. I'm 31 weeks tomorrow, and idk of its because of the lube or from not having sex in a while but at first it kinda burned a little going in. But went away after a few seconds. Should I be worried about not knowing if I have a yeast infection or did I magically just get tighter down there? 😂😂