Can i get pregnant on the rod?

Ok so i have had the rod for 3 maybe 4 months and from the time when i got it to my last period my periods have been really close like a week apart with spotting in between and there was once they were a normal length apart and now im 2 weeks late and its been almost 6 weeks since my last finished i wouldnt think it was settle that quick and so sudden either and its not like its impossible either one of my friends sisters got pregnant while she was on the rod and anyway its only been 3 weeks since me and my boyfriend last had sex because he works away and so i wouldnt really be showing any signs right? And i mean im probably just beibg completely crazy and over reacting and im going to get a test tomorrow just incase but yea