I have had two miscarriages pcos thin. I tested positive for mthr-gene and lupus anticoagulant. Should I look at IUI next time? I get period 18 days

Before pregnancy! Make sure that both you ; your hubby (if + for the mthfr 677 or 1298 genotypes), are first being treated with l-methylfolate, p5p, and methylcobalamin (at the minimum), to give any pregnancy a best chance for success. Also, do not take a prenatal vitamin that has regular fa if you are a known mthfr+ person. The regular Folic Acid blocks the receptors that need to let l-mthf through. Pm me!
See Rheumatology. I would recommend you see a rheumatologist and ob/gyn with experience in anti phospholipid syndrome . You will require specialized care to avoid future miscarriages . There is additional testing and evaluation which you will need from a tem experienced in your disorder.