Prolapsed Uterus?

I’m currently 1 week post partum, everything was healing well until tonight. I tried to use the restroom but was a bit constipated, afterwards I started walking around and felt like I have something between my legs like in my vagina. I felt around the opening and it definitely seems like my cervix is right at the opening and it feels like there’s a hard knot. This is my second baby and I don’t remember this feeling after he first. I’m wondering if it’s a prolapsed uterus? I’m going to call my OBGYN on Monday since I don’t have an appointment until the 6 week PP mark. I’m just wondering if a prolapsed uterus is something serious that I need to get checked sooner. Also if it is what is the treatment and what should I expect? Any input or advice would be wonderful.