6 plants, each one can be m or f gives 64 total possible combinations (2^6). Assuming each has exactly a 50% chance to be female...
odds of exactly 0 females = 1/64
odds of exactly 1 female = 6/64
odds of exactly 2 females = 15/64
odds of exactly 3 females = 20/64
odds of exactly 4 females = 15/64
odds of exactly 5 females = 6/64
odds of exactly 6 females = 1/64
odds of 0-6 females = 64/64
odds of 0-2 females = 22/64 or 34.4%
That's not unlucky dude. You had over a 1/3 chance of getting 2 or less females.