it doesn't say that. it says that it is possible but is harder than with same species.
Victoria would be very happy to hear you paid attention during class!
To actually answer the question though I'm not a huge fan of pregnancy stuff in hentai etc. I will def add a vaginal creampie later on, but showing pregnancy is only a " maybe " and it would be at the very very end and the credits would roll before the piglet is born lol.