When to use PreSeed

Amanda

Me and my husband have been trying for over a year to get pregnant. We got pregnant last year but ended in my first miscarriage I’ve ever experienced 😪 I have 3 kids from a previous relationship and my husband has no kids. I’m 35 and he is 46. I started tracking my ovulation again and we bought some preseed now my question is when do I start using it? At the beginning of my fertile window or when I get a positive OPK?