I'm late on my period and hpt is neg. having increased cm from clear to milky. mild cramps for 5-6 days. late by 1 day on period. any ideas?

Check for ovulation: You might not be ovulating or you ovulated later than usual. You can wait another 5-7 days and retest. If you do not have a period in 10 days see your gyn and get evalutated with a pregnancy test and if it is negative they can give you Provera (medroxyprogesterone) to start a period. If you are trying to achieve a pregnancy you can try ovuation predictor kits and see if you do ovulate. If not, have a consult.