trying to conceive

Any tips on ttc? im trying ttc #1 my bf and I have been trying for almost 7 months and my bf before him tried for a year and a half. im on synthroid been taking prenatals like the doctor said but have yet to get pregnant. its so frustrating and disappointing. i want a baby so bad as ive had 2 misscariages. i take my temperature, use the ovulation window, have sex during said window...its just getting me a little down. any help or tips are much appreciated!! thank you ladies and good luck to all😘😘