I Need You Help Ladies!!!!!?

Hello theres this girl i like in my English cl and I never really talked to her until one day when we was both on the bus. I started a conversation with her about cl and when our projects are due and etc. I asked her what high school she went to and we both found out we went to the same high school and talked about what teachers we had. She asked me where i was from and I asked her the same question back. The thing is the i forgot to ask her her name, and the next time we was by the bus stop waiting for the bus she was right in front of me and didn't even look at my direction or anything. So when we was looking for seats I didn't wanna be mean and just walk by her so I just said Hey was sup and she smiled and said Hi back. The next time I was at the bus stop again and she just walks by me and I said hi and she smiles and says Hi back. I'm not sure if she even knows I exist or interested in me because she doesn't seem to notice me when i'm around. Do you think I should try to talk to her and ask her out or is she giving me a sign by not noticing me that she doesn't wanna be bothered by me? Thank you for your input.