CD30, no AF (2 days late), BFN

Anyone have cycle problems following CP? My doc said it shouldn't affect cycle since it was less than 5 wks chemical, but... I'm late, and I'm never late. According to temps, and CM, I ovulated on CD 13. Hubs and I BD CD 10, 12, and 15 (JIC my ovulation is off a bit)... in 6 months of taking OPKS, I've only had 1 pos... and it wasn't last cycle I had CP. Just started temping 2 or so months ago. Tested $ Store hpt this AM with FMU, since some pregnancy symptoms present/getting my attention (like I had with last cycle's chemical), but not as strong. BFN. No signs of AF, no spotting, no cramping, CM creamier than my usual "dry" CM before my AF. Moderate cramping CD 26 (more than my usual), to the point I would have assumed I would wake next AM to AF, then... nothing. Cramping resolved, and.. here I am. 2 days late (not normal at all for me, always 28 day cycle, nearly to the hour or so window of start time), some confusing pregnancy like symptoms (that some could say is AF prep, but I don't usually have very many PMS symptoms at all other than same day/day before MILD cramping-sometimes), and BFN. When do you recommend I go in for blood test? Anyone else have late AF after CP? Doc said we didn't have to "wait" to TTC again, so we didn't. Any advise very much appreciated.