Rottweiler vomiting

My 3 year old female unspayed rotty has been vimiting for about 24 hours now. she started yesterday morning and its been yellow or white. no other symptoms for now. she cant keep anything down, she pukes anything i give her up in less than an hour. i gave her small amounts of water which seems to be ok. she has no distended stomach or anything. she hasnt gone poo since yesterday morning just before she started. i just cut the grass and am thinking she ate a plant or something. please advise if i should go to a vet!