Is menstrubating in large amount makes your fertility weaker?

The answer is: no

Explanation:

Menstruation is the process of shedding the lining of the uterus. The amount of blood lost during menstruation does not affect fertility. In fact, some women who have heavy menstrual bleeding are still able to get pregnant. Fertility is more likely to be affected by factors such as age, underlying medical conditions, and lifestyle choices.