Can a plan B contraception mess up your cycle?

Around the week of October 20th I took plan b (emergency contraception) 2 times. A couple days after the second time (maybe around 10/26) I got a short period, I have not had a period since, can this contraception mess my cycle up that much? Up until then i had a normal cycle, of course I have been stressing worrying about it but I have taken many pregnancy tests up until yesterday and all are negative. I just can’t believe it’s been two months with no period this hasn’t happened before after taking it.

Age: 33
Female
Medications: Lexapro, adderall xr, klonopin