Siamese cat - possible pregnancy with small litter

Question
Our Siamese has had three litters with 6, 6 and most recently 7 kittens.  The last two litters were back to back - so we wanted to give her a break.  We tried to keep the male away from her - but during the end of her heat - someone left a door open - and we heard the mating groaning - so I know he got her  at least once.  She is at 67 days today.  If she only has one or two kittens will she go into labor naturally, or do I need to have her induced.  I'm not 100 % sure she is pregnant - and is no where as large as she normally is at full term - but she's not thin again either.  She has not been in heat since this encounter happened in November.

Answer
Apologies for the delayed response.  The number of kittens should not prevent her from going into labor.  She would now be at the far end of the gestation window so if she has shown no signs of delivery I would recommend having her seen by your veterinarian.  Cats not cycling into heat can also be the sign of a reproductive system infection or abnormality so if she turns out not to be pregnant they can examine her to figure out what might be taking place.

Best of luck to you.