Not starting you period! But tests still say negative?!?!

Teána • I’m Teána, Married and 2 fur-babies. TTC for 6 years w/ 4 failed adoptions & fertility treatments. Acupuncture baby is now almost 3!❤️ PCOS & Hypothyroidism.
I am almost 15 days late, and still no period. I have taken two pregnancy tests one at night and one in the morning people are negative... Super confused! Has anyone else had this before? what was your story and what ended up Happening..? I'm needing  some kind of clarity! Thank you ladies. ?