10 months pp and suddenly a week late after being regular?

10 months pp with my first, not breastfeeding. i have PCOS and had very irregular periods before pregnancy (sometimes going months without one) but my period has been on the dot every month since 6 weeks pp.

now i’m a week late with no obvious reason (no extra stress or lifestyle changes). i took a cheap amazon pregnancy test that was negative yesterday, and the clearblue tests i bought this morning were defective so i haven’t been able to retest. i’ve also had some on and off cramping the last few days, so i keep thinking my period is coming and then…nothing.

we aren’t trying for #2 and were planning to wait until next year, so i guess i just assumed my cycles would stay regular since they’ve been so consistent post baby. just curious if anyone else has had their cycles suddenly change this far postpartum after being regular, and what ended up happening?