Are all pregnancies in the us required sti tests including chlamydia? & how early do they test you? or is it throughout pregnancy?

Difficult question: Many who achieve pregnancy have no prenatal care or access care late in pregnancy. A good full pregnancy workup would include a discussion of exposures and screening for a variety of STD's, but the extent of the evaluation may vary with the facility. New exposures would need new screening. A frank discussion with the OB can avert damage to the baby from an untreated problem.