The tricky thing about making a perfect act of contrition is that one never knows if it is perfect. So, “as soon as possible” means as soon as possible: making an appointment right away or asking the priest when you see him to hear your confession. I wouldn’t receive Holy Communion until I knew that I was in the state of grace. Otherwise, I could be offending our Lord with the mortal sin. Nothing is worth such an offense against him who loves us so much.