no period, 3 months postpartum

April

i haven’t had my period yet, but i’m three months postpartum. i’m not breastfeeding and lately i’ve been feeling nauseated, fatigued, and irritable. i’ve had some specks of brown blood (i assume it was just old blood filtering out from postpartum related things) and figured a period was around the corner, still NOTHING. anyone else having this problem? should i take a pregnancy test?