I just started my first ever homebrew

I started the brew on sunday evening and have the fermenter on a heat pad so the temperature is at about 27 deg.
On day 1 I didn't see alot of action, day 2 started to see foam building on top, and now on day 3 it is bubbling all the way out
of the air lock

Is this normal, and will it allow infection to get thru?
Thanks for any info
MikeD