Breastfeeding and TTC

We are TTC now that our son is a year old, but I've only had one period since his birth (it was in November and was 7 days of yucky blood). I've taken LH and HCG tests daily (LH) and monthly (HCG), but I've gotten absolutely zero positives... I'm starting to think that the hcg tests may be old or something because 7/10 times I test they're defective, which makes me think that the LH tests may not be too god either... Should I go talk to my OB? I'm still bfeeding, but only every 6 hrs or so. According to everything I've researched I should be able to get pregnant now. Helpppp!