Bleeding! Help!

Had a really busy day and did a lot of lifting stuff (did a bunch of grocery shopping by myself and toting around an 8 month old in a carseat 🙍and then I broke down a bunch of boxes and when I finally came in from all that, I felt this huge gush and I went to check and I'm bleeding reddish brown. What's going on!? Light-ish cramping. My pelvic floor feels like it hurts too.