There are few other good incubators around. It does not hurt to apply other places as well. However, continue to focus on your product development.
This is my first time applying at YC, but in past I have helped raised funds for other companies outside. Last year I started my company and tried to raise funds.
After a while, instead of raising funds or spending too much time in hoping to get on incubators or VCs' list I started to stay focus on the product development. So not raised any outside funds so far however my product 1.0, then 1.3 and now 1.5 is out in the market and getting real users' feedback and polishing the product.
The bottom line is don't lose attention and focus from your product and plan out for 6, 12 and 18 months out with plan A and B, in my case, also plan C.