You are going to quickly get that number up, if you are semi serious about training... it took me 2 months to get from hardly 20 up to 55.
Even though a big number is impressive, try to do the kind of push ups that are so tough you can't make more than 5. Example, putting your legs higher, or doing a one hand push up, but arm on a desk, legs on the floor.
Your strenght will drastically grow, I swear rofl.
Regular push ups will also be far more easy.