When to have sex to acheive pregnancy

My husband and I had sex 3 days in a row during the slippery stage and were very disappointed when AF arrived on Saturday. We thought we did great and hit our target day or "peak day" I am confused once their is a change in the BFP, should we be having sex everyday? I have read that we should be having sex every other day until there is a change, but I can't find anything that says what will make our chances greater at concieving, do we wait til we get slippery? Like I said we did it 3 days in a row during what we believed was slippery and that didn't work. Any advice would be helpful.