PEP and menstrual cycle

Slightly odd question. I sustained a needle stick injury at work at the hands of my attending. The patient was initially thought to be high risk and so I took a 5 day course of PEP (truvada and raltegravir) which finished a couple of weeks ago now. My period is now 10 days late (normally very regular, no other possible cause). Anyone experienced anything similar after taking these/similar medications? Thanks in advance!