Threatened abortion: This is the most likely diagnosis given the patient's symptoms of spotting and cramping at 5 weeks gestation. The presence of a small amount of blood and slight cramping are common symptoms of a threatened abortion, which is a condition where there is vaginal bleeding during the first 20 weeks of pregnancy, but the cervix is still closed.

Constipation with rectal bleeding: The patient reports constipation and a harder than usual bowel movement, which could cause rectal bleeding, especially if there was a tear or hemorrhoid. This could be mistaken for vaginal bleeding.
Urinary tract infection (UTI): The patient's symptoms of slight cramping and bleeding when wiping after urinating could be indicative of a UTI, which is common during pregnancy.
Implantation bleeding: Although less likely at 5 weeks gestation, implantation bleeding can occur when the fertilized egg implants into the uterine lining, causing light bleeding or spotting.

Ectopic pregnancy: Although less common, an ectopic pregnancy is a life-threatening condition where the fertilized egg implants outside the uterus, often causing abdominal pain, vaginal bleeding, and other symptoms. It is crucial to rule out this diagnosis.
Molar pregnancy: A molar pregnancy is a rare condition where the placenta grows abnormally, causing vaginal bleeding, cramping, and other symptoms. It can be life-threatening if not diagnosed and treated promptly.
Placenta previa: This condition occurs when the placenta covers the cervix, causing vaginal bleeding during pregnancy. It can be life-threatening if not diagnosed and managed properly.

Cervical polyp or cervical cancer: Although rare, a cervical polyp or cervical cancer could cause vaginal bleeding during pregnancy.
Ovarian cyst or torsion: An ovarian cyst or torsion could cause abdominal pain and vaginal bleeding, although this is less common during early pregnancy.