TTC - frustrated

I had a miscarriage a little over 2 years ago and I haven’t been really trying to get pregnant but me and my partner haven’t really been careful either, which is strange because before the miscarriage the only thing we didnt do to NOT get pregnant was not use condoms... so fast forward to a month ago we decided to try but we have both been busy so we BD on my ovulation day... not pregnant... I’m only 20 how did it go from being so easy to now I actually have to put effort in in only a 2 year time span? We’ve been BD’ing every day since my period and it’s only 2 days til ovulation. Hopefully things are different this month any advise from anyone who actually read the whole post ?😅😅