CM and conceiving

Hey ladies so just wondering... Me and my boyfriend had sex on Monday the 16th of June , and to my knowledge was probably my fertile time. I'm still in the fertile time for the next 3 days but haven't had sex again( while I'm writing this it's Tuesday the 17th ) just want to know is it possible to conceive? My  CM went from being thin white and stretchy like it was described to be in the fertile time and after last night ( he came inside me) I have had maybe a little bit of watery CM . But I'm still meant to be in my fertile window . Any opinions ladies :) much appreciated XX how long does it take to conceive as well and are there any tell take signs you can pick up if you have