Light pink discharge normal?

Hello everyone! So I'm 20 weeks now and I noticed some light pink discharge on my pantiliner today. It's only showed up on TP off & on when I've wiped today, so not sure whether to be concerned or not. My hubby & I did have sex last night, so maybe that caused it? We didn't have sex at all my first trimester because I'm considered high-risk (due to previous MC & a heart condition), but we've had sex regularly ever since my 2nd trimester began. So if it is the sex that caused it, this would be the first time it happened. Should I be concerned or is this pretty normal? This will be my 2nd baby & I don't remember this happening with my son's pregnancy, so I'm just not sure! Thanks in advance! 😊