Last week she wasn't sleeping enough, and now... well I'm concerned she's sleeping too much

She had her 4 month immunisations on Friday morning... She had a little fever that was brought down by panadol, and was a bit sleepy Friday arvo and Saturday, fairly happy and content and also started spacing her feeds out to 3 hours (she was feeding almost every 90 minutes during the day), and yesterday and today its like shes exhausted! Yesterday she just fell asleep sitting on my lap (unusual but I was happy as sleep has been a huge issue lately), and last night I had to wake her at 8pm because she hadn't fed in 4 hours (and because I didn't want to go to bed just to wake up an hour later LOL!).

She woke once last night, which was a nice break from the 2-3 times she's been waking... and now this morning she was awake for 90 minutes and then slept for an hr and a half, awake for 70 minutes and has now been asleep for almost an hour... our nieghbours are re-roofing, theres bagging and crashing every few minutes and Jazz just stirs slightly and goes back to sleep... again VERY unusual, especially since shes already slept so well this morning...

I know sleepiness is a normal reaction, but for how long? Should I take her to the dr? She had a cold about 10 days ago, but has seemed to be clear for a week...