How do you know when God answered your prayers? Is it possible it's just coincidence?

Once my friends were on a missions trip, and it was raining, so this dude prayed that the rain would let off for just enough time to do the next presentation to the kids. Immediately it stopped raining, but started RIGHT after the performance, just like he said. This summer I remember praying before hand that God would grab my attention away from a guy...and these past two months this guy has been in summer camp as a counselor, because God knew I needed focus. He hears you, don't worry...just ask! (Luke 11:9) :) hope this helps! don't give up!