Period came back during sex

SO and I have been together for 2 years. He's never had a problem with me talking about my period. We've also had sex while on my period before. Last night we were in the middle of foreplay and he was fingering me. When he took his fingers out he saw blood. I thought it had ended but it didn't. As soon as he saw it he stopped and washed his hands off and put his pants back on. I felt like he was disgusted by it and he shouldn't have been because it's a natural thing. Everything just stopped when he saw it. Eventually we had sex because I explained to him I really wanted it, so he wore a comdom.