Late period on the pill

Hi all! I am currently 6 days late on the pill. I take Yaz, and just started my 3rd month of it, and was on a different pill before I switched to Yaz. I am sexually active. I take it on time, the same time everyday. I have not skipped or taken a pill late at all. I’m not experiencing any PMS symptoms at all right now. I took a pregnancy test last night (was negative) and took one again this morning right after I woke up (was also negative). I’ve only been on birth control for about 6 months now and have not missed period on it in the past 6 months. Is this normal? Anyone else experience this?