Bleeding during sex

This only happened once in my life, I had sex either a day or maximum 3 days after my period ended and there was a HUGE spot of blood on the guys bed. I was so confused because it never happened to me before. My period just ended yesterday and I’m seeing someone today, I already had the light brown bleeding/spotting that occurs on the last few days. I’m really paranoid that it’s going to happen again, I don’t want to bleed. Is this a common thing that happens?