I use ovia which predicted only the begining of my fertile window as 9th jan but actually that was OV day so the days leading up to are better.
Tbf I cant comment because I followed smep to a T this cycle except dtd 5, 7, 9, 11, 12, 13, 15. So they prob didnt help. The sperm from cd 9, 11 or 12.
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