female in heat?

Question
I have a female chocolate lab that is almost 2yrs.  Although I do not plan to breed her this year I am a bit amazed that she has not gone into heat.  She is current on all shots and trim & active.  Could I have missed it?  My only other experience was with a pek as a child and EVERYONE knew when she was in heat.  My main concern is that she is an inside dog.  Thank you

Answer
She very well could have had a silent heat, and you not know. I wouldn't worry too much right now. One of my girls didn't go into heat for the first time until she was about 2 1/2 years old. You could always take her in for a checkup if it would make you feel better. But I believe that sometimes with the larger breeds, this is normal for them.