Please how do i increase my chances of having twins. usually once i have sex at the right time i get pregnant but ive never been pregnant with twins, i weigh 78 kg and im 25 years old ?

Not a good idea: Humans normally have one baby at a time. Having twins is not exactly normal, and carries added risks to the babies and the woman, on top of the risks already faced in a normal one-baby pregnancy. Risks include: premature birth (bad), twin-to-twin transfusion (bad), tangled cords (bad); higher chances of pregnancy hypertension, miscarriage, pregnancy anemia; C-section surgical delivery, etc...