Hi Dianna
Try not to worry hun I’m sure that it is not your cervix dilating. It would be extremely unusual for you to be able to feel your cervix dilating. What you are feeling is probably your labia and other tissue swelling due to the increase in your blood supply. Another possibility is as water_lilly suggests, your cervix moving which is normal. However, without being able to check you out I cannot be 100% sure so if you are still concerned it is worth seeing your midwife/ob