More sleep = more tired???

My baby started sleeping her nights this weekend but I'm finding myself more and more tired every morning. The first morning she slept through I felt amazing, but going on morning #3 and I barely have energy to burp her. My hubby says it's my body catching up on sleep. I had AF last week, along with a cold last week so I know it's not that. Could be be right? Anybody else experience something similar?