Weird tissue passing @ 28w/3d

I’m 28w 3d today. Last night me and hubby had sex for the first time in over a month. While I usually expect some sort of discharge the next day, I had a weird white, thick, slightly hard type “tissue” substance come out and it was a bit twinged with blood. Should I be concerned or mention it to my doctor today at my appointment? Baby is moving just fine and everything. I have been having some slight BH and back pain/cramping for the past 3 days. I went into preterm labor at 32 weeks with my son and was put on slight bedrest and procardia until 36 weeks. Had him at 37w/5d. They said they expect me to be early with this one too. Especially since they’re so close in age (son is 15 months and I’m due January 1st) I’m already 1cm dilated and 20% effaced. Anyone know what that tissue could have been? It was a little smaller than a dime.