Thanks for the query,
You might be suffering from a condition called as Hidradenitis suppurativa
It is a disorder of sweat glands.
Hormonal changes usually flare this condition.
Only keflex wont help you.
You need treatment with oral isotretinoin
Be careful that this drug can never be taken during pregnancy
Please meet a dermatologist
for exact diagnosis and discuss regarding this.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.