Your wife took T pill 72 to stop the pregnancy
If you do not want a baby now you should opt for more safe and sure ways to prevent pregnancy. Taking the emergency contraceptive pill
once due to accidental intercourse without planning is alright. However taking the emergency pill every time is a bad idea. It disturbs the menstrual cycle and not always sure of getting rid of pregnancy.
I would advise why dont you both see a gynecologist who can tell you the most suitable method to prevent pregnancy temporarily? Either your wife can take monthly contraceptive pills or get an intruterine device inserted which can prevent pregnancy in a better and safer way.
Till then i would say use a condom. Do not take chances and do not take repetitive emergency pills.