Thank you for the query.
Pain which has appeared first time after sneezing
it is characteristic for inguinal hernia
. It happens when during sneezing abdominal tension grows and pushes abdominal cavity contents. When in inguinal area it will find weak place, the contents will get out of abdominal cavity. You can check if there is a small lump in inguinal area. It can be present, or can appear when caught or sneezing. Sometimes it can be visualized by inguinal ultrasound
Of course it can be strained muscle, but inguinal hernia should be ruled out at first. You should visit your doctor and have ultrasound performed.
Hope this will help.