Hello dear,
I understand your concern.
In my opinion the chalmydial infection might cause
miscarriage but as the infection is treated and
blood test for chlamydia is negative it might not be the cause of spotting.
There are various causes for
spotting during pregnancy like :-
1)Thyroid abnormalities .
2)
Progesterone insufficiency.
3)Abnormal pregnancy like miscarriage or ectopic pregnancy.
4)Bleeding from cervix.
etc.
As per your information all the blood tests and ultrasound are normal.
Ultrasound helps to know the well being of fetus.
And I hope all the above causes are ruled out.
So mostly the spotting might be from cervix due to increased vascularity of cervix in pregnancy.
Don't worry in some cases even though with the presence of spotting everything will be normal as in your case and pregnancy continues till term and have good outcome.
Relax.Avoid physical stress and intercourse.
Take
folic acid and progesterone supplements.
It might subside spontaneously.
Hope this helps .
Best regards...Dr.Srilatha