On day 37 of cycle. Periods have been between 28-32. I have had PMS like symptoms for 1.5-2 weeks (lower back pain, cramps, sore nipples and very tired) but those have lessened the past 2-3 days. I took a test 2 days late and 5 days late but both were negative and I haven't had much stress at all this past month! How long should I wait to take another one? Has anyone had negative tests then a positive after a week+ late? Trying not to get my hopes up :(