Period is 11 days late!!

My periods the past few months have been on time. This time it’s 11 days late. The longest I’ve waited for my period was like 12 days. I took a test when this app said I was 6 days late, and it was negative. Yesterday on the 10 day mark, I took two more and still said negative. I always use condoms, except for one time. For like 15-20 seconds in the beginning of a session, but then I stopped him and he put one on. I’ve been checking my cervix with my finger, it’s been low and somewhat firm for days now. Any advice ? When should I go to the doctor for this? Oh yeah, My discharge a few days ago was clear and stretchy. Now it’s white and getting dry… I’m confused ??