So I may be late for my period

Michaela
I think I may be late for my period, I use X mad day as I Remember that and it was pretty precise 4 weeks after, then March 18 April 15 May 13 June 10 July 1 there's 5 weeks in July meaning then 29th or 5th Aug but it's now 9th and still no sign? Don't want to buy a test and get my hopes up as we have been trying for a year now. Has this happened to anyone else?