Starting and stopping period

I just got off the pill and this is my first real period in a long time. But I actually got my period after sex. It was 4 days long, a 3 days regular flow and 1 heavy day. It stopped for a day and a half and then after having sex last night it started up again Is that normal?

I also had sex on that day when I thought my period was done and didn’t bleed after. I’m so confused. 😬