Late period - stretchy white discharge

Hey guys! Hope you’re all okay! I’m confused as to what this could mean!

I’m 4 days late (normally bang on when due) and have this milky white SUPER stretchy CM. No clue what it is but have had it last 4-5 days and it’s becoming more frequent. Having left/right and middle cramping and sore boobs too. Any help or opinions etc would be amazing! Haven’t had sex in a week so shouldn’t be seamen but did have sex when ovulating so fingers crossed it’s positive! But I am also still having negative tests/super faint line strip tests that could be evaps or shadows