If the pain started in the lower & middle part of the abdomen and it worsened from the onset within hours AND travelled to right (that is where the location of the appendix is) then you may have to consider appendicits (as bossumemama2 mentioned) which is considered a medical emergency.
The pain in most becomes excruciating within a day.
Bringing your kness toward your abdomen would likely lessen the discomfort.
Other possibilities include bloating or wind cramps, if you experience some abdominal swelling,(as CP3kids and jemma116 mentioned) and you can try an activated charcoal capsule for fast relief.
There are many other differential diagnoses,like colitis, cholecystisis,
kidney or gallstones etc.
Should your symptoms worsen, you should consider going to the ER.
I hope you get this resolved soon.
Best wishes.
Niko
is the pain sharp and consecutive? & have you had your appendix checked lately? sounds like early stage of a rupturing appendix
It sounds like you have acute wind spasms.
As the yogurt did not seem to agree with you, you may have an allergy to it, especially the lactose. It would be wise to keep off the yogurt for the time being until your stomach settles down.
Should the pains persist and there is no relief when you pass wind or empty your bowels, then you will need to make an appointment to see your doctor. It may be that you might have enteritis and if so, it is best to avoid all dairy products until things settle down.
Until things settle down, stick to plain bland foods avoiding all dairy. If you have no appetite at the moment, that is fine as long as you drink plenty of fluids, water, fruit juices and soups (without any cream in them).
Keep a diary of what you eat and drink to see if these symptoms are triggered off by anything in particular, so that you can avoid it in the future.
How are your bowels moving? Is there any gas or bloat? Have you taken anything for the discomfort? Do you have any "bulges" in that region? Have you ever had a colonoscopy to see if there are any issues in your colon or an UGI (upper GI)to see about any abdominal ulcers?