She got pregnant and seems to be acting different towards me?

like changing her number, not calling at all, to wish me a merry christmas or nothing like that. I felt like i was there for her, seldom ignored her. Since we work together, i see her, but she's been acting strange towards me. We were never intimate, or went together her or anything like that, I 've know her since October. Also came up with a lame excuse when I asked her for a ride home last time we worked. What might be up with her? I don't think I did anything to her.