My periods are SUPER by the book. I only recently started using the <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> so it hasn't been too accurate with tracking like my older app. My cycle is 30/31 days with my period being super predictable. I cramp a day or two prior to, heavy flow first day or two, moderate flow 3-5 and then very light by days 6 & 7. Bam done. Every month. I've never tracked my ovulation. Was planning to, but my husband got sent home from deployment on emergency leave and we just went right into BDing. I have no idea when I ovulated exactly, only that we had sex on the date predicted, and a few times before and after. I started taking early detection HPTs a few days before my period and BFN. Didn't get too worked up about it. Started cramping a day after my period was supposed to start, figured it was coming. Now I'm five days late without much cramping and some very tender breasts. I've felt this way one other time before when I had  a late period that only lasted 4 days (very rare for me). I took a test today, another BFN. Assuming the tests are correct, what else might cause these symptoms? They're honestly very abnormal for me. TIA.