is it normal to have period every 18 days when on spironolactone? I wasn't able to get my period without taking pills beforehand

I'm 18, had accutane4 years ago, since then I've had problems getting my period. Cycle wasn't coming naturally (i could wait for 4 months and nothing), then I was on progesterone and started getting my period again, but cycle wasn't regular (+ 35 days). I stopped taking progesterone and waited to see if my body would take over on its own, didn't work. later I started taking spironolactone for facial hair reduction and acne, and I surprisingly got my period after 4months of nth, cycle is 18 days