Please tell me I'm overreacting...

LO is 10 weeks old, and up until the last 10 days, she has been pretty easy going. The last week and a half, though, have been a challenge. She had a reaction to her 8 week shots, but things have never really improved since then. Her sleep is super erratic, she is cluster feeding like crazy, and she has been randomly freaking out for no reason that I can figure out. She seems to be getting bigger, so I've attributed all of this to a growth spurt.

But, I'm now worried that it could be allergies. She has woken up the last few days totally stuffy. I figured that it was probably a cold or airborne allergies-DH and I both have them. But I was reading on Kelly Mom that congestion can be a sign of food allergies?! So now, of course, I'm worried that there is something in my milk making her sick, and I'm freaking out a little bit.

Thoughts? How can I tell-just wait it out? I don't want to overreact, but I also don't want to be making her sick!