I lose mine throughout my pregnancy starting around 6 or 7 months im also 32 weeks. Ive been havin braxton hicks contractions on and off for a while that might be what it is. But just in case just call someone and let them no you can lose ur mucus plug weeks before u have ur baby. But by losing it it means your close . :)
Im wondering if the pinching is like a sting in your cervix, i get that and im 28.5weeks. As for the plug it regenerates so because there is no blood it could just be your vagina cleaning itself. But in your case, Because you had the contractions i would call your midwife in case you need assessed. Best of luck