Bleeding but heartbeat??

Hi Ladies, has anyone experienced bright red bleeding and carried to term? 5 days ago I had a big gush after walking up some stairs which tapered and yesterday I had another smaller one after some vigorous vacuuming (clearly my partner needs to take over this duty). It’s pretty scary and clearly fresh blood but I had a US 3 days ago with heart beat 115 at 6wk1d and hcg at 12000. This will be my second pregnancy and with my first (2 years old now) I had no bleeding at all. Have also had substantial cramping (not intense but frequent) which is quite new. Any thoughts? Advice on what it could be? I’m going to go a little crazy if I can’t exercise at all as I’m normally quite active but also want to protect the little embryo <3