First don't panic. I have a 2 year old and an 8 week old and they are/were both "spitters". My daughter spit up constantly, with every feeding, breast milk or formula, it didn't matter. And she would launch it too. We tried a couple of medicines with her and they made no difference so we dind't continue with them. She kept growing and gaining weight so the doctors weren't really all that concerned. They told me I had more of a laundry problem then a medical problem and boy were they right. She would spit up immediately after a feeding ALOT and then moderately between feedings. Her spitting up never bothered her, she wouldn't cry or act like it hurt or anything like that. She continued spitting up like that even after we introduced solids. I believe it wasn't until she was 8 months old when she finally stopped. We celebrated by having our carpets and couches cleaned! ha ha.
Now my son is a little different. He's been diagnosed with reflux and he too spits up a lot but not always immediately after a feeding and when he does spit up, it's often painful for him. My doctor prescribed Pepcid for him. We give that to him twice a day and though we haven't noticed too much of a decrease in spit up, we have noticed that it doesn't hurt like it did. My doctor also has me put rice cereal in his bottle to help keep it down. That can be pretty controversial so don't do that without first getting the ok from the doc.
You'll have a well visit in another week so make sure you note when he spits up the most (morning feeding? night feeding? all day?) and if it seems painful for him. My understanding is that this is a fairly common thing and either it just has to run it's course as the case with my daughter or he should receive medicine as with my son. Just don't worry, as long as he's gaining weight he's fine!