I really want to get pregnant, what are the chances?

The last time I got pregnant, my boyfriend and I had sex once on a "fertile" day and I got pregnant instantly. This made me believe that both my partner and I were really fertile as it was so easy. I had sex on Thursday a "fertile" day and just desperately want to be pregnant. I'm just wondering what the chances of it again being so easy are? Is it just wishful thinking, I'm sure it does take ages to try