Can I be pregnant ?!

I had unprotected sex on the 19th , 23rd &’ 26th of July. I took plan B after I had sex on the 19th &’ the 23rd. I had a heavy period on the 28th that lasted up to the 2nd of this month. I’ve been noticing weird symptoms like feeling very nauseous &’ super bad headaches. Tonight I noticed my boobs looked odd and I squeezed and watery substance came out of both of them. I just had a baby 11 months ago and I’m terrified. I breastfed her for 3 months and thought maybe its just old milk ? Help please 😫😖 am I just overthinking?? Or can I be pregnant.