ER or Pediatrician Delimma

I called the cardiology clinic early this morning to tell them that my son was vomiting with blood in it. Gerald has been on warfarin (blood thinner) for couple months now and we haven't have the perfect result of this thinner. Anyway, the nurse that took my call told me to take my son to the ER. I was  reluctant to do it, because GJ was looked really well and he was at school at the time. I was strolling back in forth in our living room when I decided to just call several doctors. They all got back to me and told me the same thing to take him to the ER , but also gave me an option if my pediatrician will take him and not sending us to the ER. All of this dilemma is just the cost of going to the ER versus the regular doctors. If Gj was not in good condition, I don't need to call any doctors office and we will just go straight to the ER. Oh, believe me I am a panic person. Anyway, my husband took GJ to the pediatrician and he said he was fine. Thank God! No need to go to the ER since it is not surprising to see some  blood in the sputum if you are on the blood thinner ..I guess as long it is not a lot!