Help!!!!!!!!

Natasha
So curiosity got the better of me ... I downloaded some more fertility apps and i now have 2 that tell me today's the end of my fertile week... Glow tells me it ends Sunday and ovia tells me it ends Saturday and clue and kindara tells me it ends today ... So I have sex everyday since Saturday, have I missed it? I've been using preseed. I don't do opks or bbt because well I don't think I'm at that stage yet! 
I had a scan last month on the 15th March because I had acute appendicitis and the sonographer told me there was a follicle in my tube so based on her statement I would presume I ovulate on the 15/16th of the month? 
Help!!!