What can cause multiple LH surges?

Period started June 15th-19th

Positive ovulation test july 5th. Test line slighter darker than control line. Lines stayed the same amount of darkness until July 15th, then the test line was a LOT darker than control so very positive. Now july 17th negative. HCG tests negative.

Could I have just ovulated late? Does LH surge right before period? What is happening?

I have pressure and light cramping, headaches and nausea but I get all that before AF too so idk.