Dog limping

[It's been a month]

I took my dog on a hike 3 days ago and she ran around crazy and had the time of her life. Running and jumping up and down the hills, chasing the birds. Well, now she is now limping. I can tell it is her front left leg/paw that is bothering her but cannot find anything. I have looked, squeezed, felt, etc up and down her shoulder/leg and found nothing. I rubbed her paw, felt all inbetween her pads and nails and still can't find anything, nor does she flintch when I am doing this (I have done is several times).
Is it time to take her to the vet, or should I wait it out a couple of days longer. I am thinking it could be a pulled muscle or something, as she was running all over but really don't have a clue because she doesn't react (at all) when I am checking her out. Is there anything I can give her at the present moment to ease the pain when walking?
Thanks!
Female/7.5 years/Golden Retriever - she is a good girl :)

[It's been a month]

I was planning on trying to wait it out for a few more days, but seeing her hobble around is so hard. Thanks for your input, it is most appreciated.

[LoriBug]

I would wait another couple of days and see how she does. Try not letting her run too much on it because it probably is a pulled muscle. Less activity the better to let it heal. If it is not better in a couple of days I would consider the vet, and they will probably give her an anti inflamitory. Sorry your dog is hurt. :o(