It is OK to be anxious about being anxious during pregnancy?

I often get a bit anxious before a big life change - moving overseas, getting married, a new job - once I have tackled the change, I'm fine. I am now 5 weeks pregnant and although I was overjoyed when I found out, I am suddenly overwhelmed and anxious x 100! I am also finding it hard to pinpoint my anxiety to one specific thing - this makes me think that I am actually anxious about being anxious rather than any one part of being pregnant. Did anyone else feel like this?