TMI. Big blob of CM? Confused!

Beth
Can anyone help, really sorry if tmi but went to the toilet this am and big blob of CM appeared? For the last week I've suffered with cramps, moods, bad back, headaches and due tomorrow (3rd may). Wondering if I have a longer luteal phase or maybe that's it's good news? Did a test two days ago and was a BFN. Advice welcome please! Xx