Thank you all so much for your responses. I sure was shocked and they scared the heck out of me especially since Mikki is 5.5 lbs. and Max is 12 lbs. ... They really took me by surprise b/c I didn't even know that Mikki was in heat, no bleeding, no exessive licking, nothing...
We had Max neutured 1 week after we got him last year in August and planned on having Minnie and Mikki spayed end of October after Mikki reached 6 months of age. Well... beginning of September first Minnie, 11 months then, got in heat and then Mikki followed 2 weeks later at the age of 5 months and 2 weeks very much to our surprise. When they both were done we got word that we had to move in November and wanted to wait with the spaying b/c our vet in MD was about 20 miles away and we hoped to have one closer here in ABQ...
Mikki is wearing a diaper now and I watch the two fellons like a hawk b/c Max tries to take Mikki's panties... uhm... diapers off...
I'll call our vet tomorrow and ask if I have to bring the two in. Oh... Max is Minnies biological father and was used as a stud before we got him. We know of at least 4 litters he fathered...