could it be sleep regression?

Maggie
My baby has gone down at 10 each night since she was born and would wake at 8/9.  Started sleeping through the night at 2.5 months.  If she might wake up we would just go put the pacifier in, put on the white noise machine,and rub her belly back to sleep which worked. Now at 4.5 months and with me back to work , I put her down by 9 -930PM. She has been waking up every couple of hours bright eyed and bushy tailed.  Could this be the four month sleep regression? If so, anything I could do?  Should I dream feed?  She is up by 5 each morning.