CBEFM Question - Help!

Hi! I've been hanging out in the TTC after m/c for a little bit. I had a d&c in October, and I'm now on CD13 after my first post d&c AF. That AF was 31 days after my d&c, so a little longer than my normal 28, but not bad at all. I broke out my CBEFM for this cycle, but I'm still getting a low reading. I should definitely have an elevated reading by now. My peak days are usually 15 and 16. This am, I noticed my strips expired last month, so I'm wondering if that's why I'm still getting low readings? I'm going tonight to get some more, so hopefully it will read elevated tomorrow.Since they're just one month expired, I wouldn't have expected this, but I was wondering if anyone else experienced this?

Thanks!

Jennifer