How many days after lmp is safest to go for scan to avoid false results n associated stress.can we skip transvaginal n wait for ultrasound scan later?

Scan for what?: That depends on what the goal is. If only worried about pregnancy, couples can just do a urine pregnancy test. There are very, very accurate. Home pregnancy tests not affected by foods, herbs, common illnesses, sexually transmitted diseases, or medications. A correctly done urine test gives a reliable result 3 weeks after sex, 1 week after starting a "weird" period, or 1 wk after missing a period.