Cefdinir side effects or Cdiff?

I got prescribed cefdinir for a recurring case of tonsillitis. The night I took It my stomach hurt really bad. Im on day 3 and still have watery stool but no other symptoms. Im taking a gut probiotic with the cefdinir, an avoiding foods that could upset my stomach. Is It possible I just am having a side effect??? I cant afford more Dr visits and could barely afford urgent care for the tonsillitis. I have to finish the full course, 300mg twice a day and Im taking a gut probiotic In the morning with 2 hours between the medication. I have OCD really bad and this is weighing on me very heavy