What do they do at a colopcopy during pregnancy? why does it hurt so much?

Just inspect & Pap: A colposcopy in pregnancy is simply a pap smear with the scope for improved visualization. Biopsies are usually not done, endocervical biopsies are not done. Usually just a pap is done which should not be painful. It should feel no different than any other pap. A dilute solution of Acetic Acid (vinegar) is also used and this may cause mild discomfort, and is usually wiped off afterwards. Take care.