What does it mean when your girlfriend or a female says this? ?

Me and my girlfriend will be dating for 2 months and she texted me saying you know its almost 2 months? And I said I know baby..she said you know what that means? And I said what baby? She said can't tell you :). I said no fair..then she said its a surprise for you and I said give me a hint and she said it deals with sex...so does that mean we are going to have sex? Or oral or what? If we were going to have sex she would say we are going to have sex right? Let me know what yall think..thanks alot