I have been using the clear blueadavanced fertility Monitor this is my second cycle and I knew the first cycle you would just get high for more than a week due to it getting used to me but it has done the same this month any ideas why it's not picking up a LH SURGE ? I tried the simple cheap Opks but didn't get one on them either ! Any advice? We use preseed or conceive plus lubricant and both take a conceive vitamin tablet.  I test on first morning urine between 5-11 depending on work. We have be trying now for 18months but I have had previous gynae surgery so don't know if it's linked to that any advice or ideas appreciated