Test for your LH surge 2-3 times a day!
Test 2-3 times a day and start with your 2ND URINE!
I almost missed my LH surge because I was testing 1st thing in the a.m. and once a day.
Then...on CD17 which is a later ovulation time for me...I tested at 11:30am and it was freakin' purple : ) No doubt about it.
Went in today and had my IUI! Nurse said cervix was open and great cervical mucus showing that I more than likely have or will be ovulating. Perfect timing. Whether it takes or not is another story but please consider testing 2-3 times a day so you have test lines to compare. You'll know it when you see it.
On another note...PAY ATTENTION TO YOUR BODY around your expected window of ovulation! My good friend didn't have a positive LH surge but felt like she was ovulating and ran to her RE, had IUI and now has a beautiful 2yr old boy from that IUI.
Keeping my fingers crossed for all of you attempting mommy-hood!