First off, what is "Mendes"? Secondly, how old are you and are you taking any supplements or medications? Both can play a role in vaginal lubrication. There's also a chance that you may have an infection that isn't allowing your vagina to lubricate pre-intercourse. Also think in-depthly about how the foreplay is going between you both. Is he doing everything he needs to do to stimulate you for sex? If not, try having him perform oral sex before intercourse. You could also try to achieve an orgasm before intercourse as this would typically lubricate your vagina. Lastly, you can also use a water-based lubricant to help, and sometime this even stimulates natural moisture to occur.
I am 27 years of age and that was supposed to be menses