That reminds me, last time I was at the shopping district I ran into Sakurako.
I recently bought a Japanese music CD.
When was the last time I saw a sunset so perfect that I had to take note of it?
この means "this." And, you know what the word 前 means (front/before). So "this before" has to do with something that happened previously. That's why this word means last time, recently, and lately.
The reading for 前 is the kun'yomi, like the reading for the vocabulary word 前. So long as you know that word, you'll be able to read this one too. The reason it's not on'yomi is because it's like two words put together. The word この and the word 前.