There is no "pill" for cats, at least there isn't one that's safe.
Definitely you should get the male fixed so there are no "accidents." However, an unspayed female is not easy to live with. She will yowl, spray urine, and be generally obnoxious when she's in heat. She'll also become very sneaky about trying to get outside; and if she does happen to sneak out, she will be ruined for breeding, you will not be able to guarantee purebred kittens, and there goes that idea!
Unless you are prepared for a lot of annoyance and sleepless nights, not to mention the normal expenses of top-notch food and vet care, and a good padding of funds should anything go wrong, breeding is not such a terrific idea. A lot of people think "Oh sure, one litter, I'll make a little money and all will be great." That is a myth. Breeding is an extremely expensive hobby!
I don't know what the pet population is like in Sweden, but if it's remotely like here, there is not really a good reason to bring more kittens into the world.
Cheers,
Dr. Jean