Is this reflux in 8 week old baby?

[Hotmad]

Hi my DD is 8 weeks and for the last week she has been possetting more than usual and vomiting sometimes after a feed and sometimes an hour after a feed, not all feeds and not at any particular time of day. We started off breastfeeding then combined and now for the last 2 weeks the formula has Been increased so I wonder if this has triggered a problem? We use aptamil first stage. We went to dr the first day she was sick about 5 times and they wasn't concerned, thought a bug. Seen again by dr a couple days after and she had reduced sickness to just once or twice that day and dr checked her and was ok, no real definite conclusion but since then she still been sick and sometimes 1 or 2 times and sometimes 4 or 5 like yesterday. She seems to be quite upset by the vomiting not the possetting though. She seems to get windy during feed then I burp her and she is sick or hour later despite winding and sitting up for 20 mins after feed she can cry and then vomit. I will see dr again on Monday but do you think it's reflux? Or should I be more concerned?