Which one counts as my actual surge?

I've never in my life had such strong positives. For 24 hours now I've had test lines darker than control lines. I'm now cramping in my lower abdomen and lower back at 4am. What does this mean? Why is my lh so high!? Does this mean I'm ovulating more than one egg? Does it mean that I'm having trouble ovulating? I'm going to have an ultrasound of my follicles and my uterine lining today. Last cycle my lining was at a 1.5mm. It was devastating. I'm hoping that it's thick enough for implantation now. What does this mean? Has anyone else had this? Could someone explain it to me? I'm so excited yet nervous.