Feels like I'm on my period but....

Nothing! I'm so frustrated. My son is 4.5 months old and EBF and I stopped bleeding at 4 weeks pp. For a week now I've felt like I'm on my period, even felt a little gush and thought for sure I'd started but it was just an increase in cm. Why is this happening? How long should I expect to feel this way before I finally start!?