As others have said, you could just have a spitter-upper. Our baby started spitting up at about 4 weeks and was a spitter all the way until about 1 year, long after she was sitting up, crawling and even walking. It was after every feeding until she was on solids at 4 mo., then it started decreasing very gradually until about 10 mo. when it was down to about once a day. She still spit up occasionally until about 13 months.
Talk to your doctor -- if you have a happy spitter (never seems uncomfortable during/after spitting up) and your baby is gaining weight and sleeping appropriately you DO NOT need reflux medication. As our doctor said, spit up is a laundry problem, not a medical problem.
For us, things we did to alleviate the problem: burping every few ounces, slowing down (she was a slurper!!) her eating as much as we could by taking the bottle out of her mouth for a rest every few minutes, keep her upright for 20 or 30 minutes after the bottle's done. We never, never, never held her without a burp cloth handy and warned everyone who held her to watch out! She frequently would spit up with a smile on her face so we knew it wasn't a problem.
We also switched to using a portion of Enfamil's A.R. formula which is a heavier weight and intended to reduce spitting up. We could not use it 100% because it led to constipation, so we gradually tried different proportions mixed with regular formula until we settled on one that worked. The proportion changed over time as she spit up less. So for a 6 oz. bottle, we started with 2 scoops A.R. to 1 scoop regular. By 8 mo. for an 8 oz. bottle we were doing 3 scoops regular to 1 scoop A.R. We kept trying to eliminate the A.R., but her spitting up would always increase. Once she was on mainly baby food, we added rice cereal to everything and moved ahead to the Stage 2 or 3 foods very quickly because they were thicker. We tried anything to keep the food down.
Point being -- try whatever might work, but don't worry about it after you confirm with your doctor that your baby is just a spitter. It will end!
p.s.: we just got our carpets and sofas professionally cleaned to clean up all the spots she left behind! It took everything out, no problem!