Late period - medicine?

My period is 12 days late now. I've been on a pill for over a year, then had to stop taking it due to medical reasons. My previous period, the first one after getting off the pill was only two days late, so I expected this one to be on time as well. I've already taken pregnancy test on Wednesday but it was negative. We've been using condoms since I'm not on the pill anymore, but I'm still afraid I might be pregnant. My question is - can following medication affect my menstrual cycle? I'm currently on Betaserc (betahistini dihydrochlorum, 24mg, it's for my vestibular neuronitis), Setaloft (sertralinum, 50mg, anti depressant) and Letrox 50 (levothyroxinum natricum) - the last one is for hypothyroidism I suffer from. I know this illness may affect my menstrual cycle, but I'm on a medicine (Letrox) which is supposed to even out my hormones, so I'm not sure that's the reason of my period being late, especially that the previous one was on time