On P.O. Pills but no period yet. Am I pregnant?

I have been taking Progestin-Only Pills since like February and I went off of them for a month in July when my boyfriend was out of the country because I thought it was unnecessary but when I started getting mood swings, I went back on them. Anyways, it's been almost 3 months since I have been back on the POPs and my periods haven't been regular. My first period I had on the 4th week of the pills (because they are all active) then the second pack, I had it on the second week of pills, so I was expecting my period to come on the second week of the third pack of pills and it came on the 4th day of the 2nd week. I was scared because I thought I was pregnant, but now I'm experiencing the same delay. I should've started Monday and it's Wednesday. Do I assume delay or should I take a pregnancy test?