Ovulation test question

So I have been trying to conceive for more than 6 months and have been having issues with the ovulation tests. I started with femometer tests and not once did I get a positive test. I decided there was something wrong with me so I went to the gynecologist and have had several ultra sounds as they were finding cysts on my ovaries and the largest was 4.2cm. I guess I should let you know I have pcos and endometrial fibers forming. They were concerned as 5 cm is surgical as it can cause the ovary to twist cutting off circulation and killing it. Anyway back to the real issue, I decided that those tests were bad. I switched to clearblue advanced digital tests and the first few cam up negative but then surprise I got an LH surge (blinking smiley) and I got that for 4 days in a row then I ran out and had to purchase more. So the first test came back negative. I was a bit shocked but I decided to take one later in the day only this time using the reader from the first box and it came back with the blinking smiley. Am I crazy? Is it possible to have tests that are different readings from the same day? Is it possible that the reader is bad? I plan on doing 2 tests tomorrow one with each reader to see if it is the reader but anyone know if that is normal or just my luck?