Help--created massive user error with cycle calculations

I thought that I had accidentally reported that my period started (it hadn't, I'm late) so I deleted that period, but it created another one in the future. The new projection is way past my cycle but I can't get rid of it and can't get the program to reset the predicted days based on my actual cycle length. (If I manually add the correct days for what my current period should have been, it still shows another period happening in two weeks, not 31 days.) I've basically managed to render the whole app useless to me. Is there any way I can fix this?