can u force doe to be in heat

I have a nubian that has possible due dates from nov 28-jan5. Her belly isn't growing. I don't feel anything. No udder. And vulva goes from puffy one week and the next its gone.

Not sure what else to try. The rut season is coming to an end soon. The buck is proven. She's in w him now. They get along well. Maybe she's not coming into heat? She's my healthiest goat. Perhaps a little overconditioned, but I can't get her weight down much. She's got a big rumen. When she eats less just her back sides get hollowed out but everything else stays the same. She's just on grass hay no grain.

I bought them last jan. They were in the same pen so came from same place. Owner didnt have them long so no history there. He got them together as well. Maybe they're siblings.? They would still breed though right? Don't know. I'm running out of ideas. He's the only buck I have. Have a bucling but he's young and she picks on him.
I think she's a ff too. Can't feel any tail bones like you would on on one that's kidded before. Have never seen discharge on her either.w all the other ladies I've noticed wet tails or actual white discharge after being in his pen a while. One I actually had to take out after two weeks. I don't think she was eating much due tohim trying to breed her everyday.