ttc but he works away so much

hi guys I had a miscarriage febuary and had my first period 22nd March my parnter works away alot and I am in my fertile window he goes away tomorrow (tuesday) and won't be back until Friday we BD saturday and going to tonight and tomorrow morning I hope this will be enough as I've been told your more fertile after miscarriage i have bought some preseed too but don't know if to use it or not yet... not sure if preseed will help sperm live longer up there or not had anyone else been in a similar situation and conceived not on the day they ovulate praying for baby dust