Hi My 2 1/5 Year Old Has Strep And Had

hi my 2 1/5 year old has strep and had gotten a penicillin shot this morning. yesterday i found that she had a swollen lymph node one her neck the size of a golf ball and hard as a rock. the dr this morning said nothing about it. it is very painful for my daughter and she can barely move her neck. im getting worried. should i just wait it out for a day or so and see how she reacts to the medicine or should i take her back to the dr