Pregnant?

Just curious as to how many women have had there period while being pregnant. I had a baby 4 months ago & I'm currently on my monthly cycle but I'm also feeling nauseous & have been for almost a week an a half now but I've never had my period while being pregnant or felt nauseous while being on my period so is this normal ? I did have sex on the 8th but our protection didn't really work which is why I'm stuck now with what is going on?

Please no rude comments