15 DPO. Period Is Late. Negative Test. Please Help.

So my cycles are usually 28-32 days long.

I usually spot before my period shows.

This month I have had no spotting.

I have had severe back ache.

I have had cramps like period is going to start, but not as strong.

But no signs of AF.

I tested yesterday and it was negative.

I am now later (later than the 32nd day which is usually the longest time)

I’ve been having milky discharge for the last 5 days.

Help please.