Some vomit in the early stages and clean out their stomach before hard labor begins. If you are concerned about anything the best thing is to call your vet and double check just to make sure things are probably okay after they are able to get all the details. There is more detailed information and links for you in the links. Don't forget her post whelp exam about 24 hours if things seem to go well. Good Luck.
http://drnelsonsveterinaryblog.com/2009/01/01/canine-labor--when-to-call-the-vet.aspx q3525724.html#a2810229 q1679449.html#a2947871 q2722771.html#a3046267 q5851064.html#a3054016
q5762034.html#a2906893
http://www.wildheirlabradorrescue.org/readingroom/what-is-a-back-yard-breeder.php
http://members.tripod.com/antique_fcr/goodbreeder.html
http://www.petfinder.com/index.html
http://drnelsonsveterinaryblog.com/2009/01/01/canine-labor--when-to-call-the-vet.aspx q3525724.html#a2810229 q1679449.html#a2947871 q2722771.html#a3046267 q5851064.html#a3054016
q5762034.html#a2906893
http://www.wildheirlabradorrescue.org/readingroom/what-is-a-back-yard-breeder.php
http://members.tripod.com/antique_fcr/goodbreeder.html
http://www.petfinder.com/index.html
