Oh my gosh no, your therapist is way mislead. There is no medical reason why we have placebo weeks or day while on birth control. What the bleeding is isn’t a true period because that would need ovulation to occur as periods are shedding of the uterine lining and broken down egg. While on birth control our cycle stops and we don’t build up a uterine lining or ovulate. What our “periods” are while we’re on birth control is our body withdrawing from the hormones on a cycle which causes what little uterine lining we have to be flushed out as our cycle restarts. Then we go back on the hormones before ovulation can occur. This is why periods are much lighter or even nonexistent while on birth control most of the time. Doctors just originally put the placebo pills in because they thought it was psychologically better if people on the pill felt like they were on the same cycle. It does nothing medically. It is perfectly safe to skip placebo/withdrawal weeks while on birth control, although it’s best to talk with a doctor beforehand.