My period is 10 days late and I am frequently regular. I had severe cramping today and 3 negative pregnancy tests so far. I ovulated July 24-30 and had sex the 25th, 26, 27, 30, 2 and 9th using the pull out method. We have been using this method for 3 years since our son and have been successful in not becoming pregnant. Any advice for me. Could I not be pregnant?