Sleep Protest!

Hey there!  Haven't been on here in a while.  Had a question to compare.  Our little Hailey at 10 weeks has decided for the past four days that she was just not interested in sleeping at night!  She was on a great path with only getting up once per night.  Usually going down for her long stretch of sleep at 11pm-6am.  Now, she is getting up a lot, not letting me put her down.  Acting like she is out cold and then the minute I put her down screams horribly.  She had been so easy going the past month so this all really surprises me!  She is part breast milk and some formula, we did switch her from newborn to infant this week.  Do you think that is it?  Growth spurt?  We are doing the whole sleep routine, unfortunately with our work, she starts her sleep routine later at about 730-8.  No fever. I know babies change their schedule all the time, the only thing is that she can go down for normal naps no problem, it is just at night she will NOT let me put her down for anything and if I try to let her cry a little, it turns into the not breathing kind of cry which she only does if she is REALLY upset, and there is no coming back from that unless we start over.  Thoughts?