pregnancy symptoms disappeared at 6 weeks

I'm wondering if anyone can help me. This is my second baby so I don't know if that changes things. The past week I have noticed my symptoms disappear I sometimes have occasional nausea in the morning but I just eat something dry and lye back down. I noticed today that my hair was falling out (I had constipation yesterday so don't know if it's iron deficiency) has anyone else had this? My boobs are no longer sore and the nausea is about the only things I have.