is it possible to be pregnant breastfeeding!?

Erin

I had my daughter 11 weeks ago I haven’t had a period one day in January I had a spot of blood in underwear but then nothing so Idk if that was my period trying to come but couldn’t i would think you could get pregnant that fast breastfeeding I’ve been nauseous the past two days now with headaches on and off one minute fine the next feeling like I’m gonna be sick and lightheaded that’s the only thing that made me think 🤔 is it possible