Came off the pill had unprotected sex and now I’m spotting

I came off the pill on the 17th of this month and had unprotected sex on the 19th and last night I was cramping really bad all day I just thought it could be my withdrawal bleed starting but then when I went to the toilet before I went to bed there was a small patch of pinky red blood in my underwear but there was nothing when I wiped and there’s nothing this morning, my friends says I could be pregnant but it seems too soon to me I only came off the pill 6 days ago, can anyone help me of that has be through something silmiar, I think I’m just to excited we want to have another baby and I’m thinking to much Into it.