Check if your period is late, and, if late, how late. Just fill in the
date of your last period and your average cycle length.
If you're a member and logged in, the date of the last period you recorded
in MyMonthlyCycles is filled in; And, if you've tracked at least 1 cycle (two
adjacent periods), your average cycle length is calculated and shown. To
what-if calculate, just change any of the pre-filled info!