My 2 Year Old Son MIGHT Have Ingested Some Massage/bath

My 2 year old son MIGHT have ingested some massage/bath oil. I am not 100% sure since I did not see it. He ran into the bedroom and was playing on his bed. I went to the bathroom and when he came back to me, he smelled of the oil. I went and checked and it had been knocked off the shelf somehow and the cap broke off. There was a puddle on the floor and he smelled of it, including his mouth area. I'm not sure if he just touched it and touched his face or if he tasted it or actually drank it. He hasn't told me, just keeps saying he held it, says no when I ask if he drank it, but not sure he'd tell me the truth anyway. I called poison control and his pediatrician. PC says should be okay, to watch for respiratory distress, coughing, vomiting, etc. DR says if I'm worried go to the ER. What should I do? I've been watching him sleep for an hour now, crying, because I'm so scared. The incident happened about 3 hours ago now.

If something were going to happen, would he have shown signs of it by now?
Should I take him to ER just to be sure?
If I do, what will they do for him there... how will they find out if he is in danger?
Any advice, help, information will be helpful. I am terrified right now from what I've read online.