Before you trademark the name, which is moderately expensive, let's take a look at the brand name / domain and ensure that it's really the identity / web address you'd ideally be married to for the next 5+ years.

Quite possibly the name you're working with is perfect for you. But it's worth scheduling a checkup with an expert while your site is in beta. I can give you a green light or point out issues if there are any.

Even if the brand name is ideal, your domain might not be the best implementation of that brand name. And even when the domain and brand name match closely, there can be other domain-related risks from which a trademark won't necessarily protect you.

I don't want to scare you unduly about the name. Just take that "car" to a "mechanic" before you go on a gigantic "road trip" with your startup site, including advertising costs, trademark, etc. Have it looked at.