My 3 year old female Yorkie poo has started peeing and pooping all over the house. I got her when she was 4 months old, from birth she was trained to pee on a pee pad all the way up until she was 2 and then I did both. I would let her do her business on the pee pad whenever she needed but I would also take her outside, and for months she was into that habit - we had no problems. When she turned about 2 1/2 she started peeing in my room under the bed... And would only do it when I was not there or when I was not keeping an eye on her (I trusted her). So I started crating her while I was not home but not while I was home sleeping, and she did perfect with that.
Now we moved to another state, and I had her on a pee pad only, it took her time to get used to it (which is normal) but eventually she got it and she continued her routine (without peeing in my room). Then started peeing and pooping in our spare bedroom, I scolded her and ignored her... even brought her mess outside to show her where it should go. At this time I could not crate her because I did not have one at that time.
We were forced to move again and I rid of the pee pad all together. She was doing fine, holding it till I got home and then doing her business while having her freedom all day. She went in the morning, when I got home, and before I go to bed. Now I am pregnant and home so she is able to go all the time. Once she got that leniency she started peeing and pooping in the house. So I switched her back to the schedule she had, as if I was at work. It worked for a week or two and she started up the same thing again. I got a crate and I have been crating her at night (because she started peeing and pooping then too).
NOW, IT HAS GOTTEN OUT OF HAND I leave the house for five minutes (trusting her to behave for that short period of time) or less and she pee's in the bed as well as poops on the kitchen floor after she was just out 15 minutes ago (she pooped and peed). I have left her alone out of the crate before for 10-15 minutes at a time and she would not have any accidents, so I just do not seem to understand at all.
In 5-6 months I will have a crawler in the apartment and it will not be at all sanitary or safe to have this habit of hers keep up! I have tried everything imaginable. I have rewarded good behavior, big bones to keep her mind off the accidents and I have not came up with a solution. I am in need of some serious help with this situation because once the baby gets here I would hate to have to crate her more just because of her accidents (that is not a happy thing for her to be locked up all the time) I would like to nip this in the butt ASAP

You can't attribute human attributes to a dog when it comes to this, such as 'leniency' giving her some sort of freedom to go wild; it has to be related to confusion and uncertainty and anxiety. Also, ignoring her is not meaningful in this regard either. She just has had to many changes in her routine, and dogs are all about routine. Plus, she now has smelly spots all over the house. Part of the solution is bleaching and scrubbing them, as well as closing off all doors possible if she isn't in her crate. My little dog is getting old and just doesn't want to go out in the cold, rain, or snow. I have to take her out and praise her profusely for going, but I also have to have some paper towels on the bathroom floor (she always goes in front of the toilet, which is endearing but not so great if it's the middle of the night and I can't see it). And I keep all unused rooms closed off, and barriers across openings with no doors.
Some dogs don't handle babies well, and I have known people who just couldn't keep the dog.

You are treating her like she is human with human thoughts and emotions and reactions. She is NOT human; she is a dog and needs frequent and consistent training. Pee pads, first of all, are a no-no. You have trained her to pee and probably poo on anything soft.

I know all this from reading this board and all the good advice given by dog experts. Stay tuned, and they will advise you too so you and your pup can get on the right track.