faint positive pregnancy test

well my obgyn told me I wasn't able to get pregnant this time with out fertility treatment 4 months ago but lately I've had head aches and peeing constantly. so this morning I took a test. It's a faint pink positive with a first response but it's there for sure! my baby girl turns 1 this month and I may be pregnant again! I'm in shock lol. We are not telling any one so I needed to vent some where and tell some one!!! also I'm breastfeeding and haven't had a period since birth last November! So I'm super shocked!!