The cost of a loss of working hours in such cases would be covered by the state for as long as the pain lasts, the government confirmed on Monday on request.
A consultation with a doctor is required to get the time off work.
Adopting the legislation would make Spain the first country in Europe with such a law.
Equality Minister Irene Montero of the smaller left-alternative coalition partner Unidas Pomedas is one of the main forces behind the bill.
It is due to be introduced as part of a new regulation on abortion law, which will allow all over-16s to terminate a pregnancy without parental consent.