Cramping after ejaculating inside does not necessarily indicate pregnancy. There are many other reasons why you may experience cramping after sexual activity, including muscle strain, dehydration, bladder issues, intestinal issues, and gynecological conditions such as endometriosis or ovarian cysts. However, if you have unprotected sex and are experiencing cramping, pregnancy is possible. Cramping can be the first of many signs of pregnancy as the fertilized egg attaches to the uterine lining. Other early signs of pregnancy include missed periods, fatigue, nausea, and breast tenderness. If you suspect you may be pregnant, taking a pregnancy test to confirm is essential.