How can you tell the difference between normal pregnancy symptoms and ectopic pregnancies/miscarriage? cramping is normal in all these how do you know

Ectopic Pregnancy: Ectopic pregnancy may be suspected if a woman has abdominal pain with peritoneal (surgical) signs indicating a surgical consultation is immediately needed, especially if she is hemodynamically unstable. If a woman has milder pain, +HCG >1500, transvaginal ultrasound is very useful but not 100%. If fetal heart tones seen and gestational sac seen with +HCG can rule out, if not seen serial HCGs/ D&C.