4 month old Chihuahua female/sleeping alot

Question
So. Our puppy, Binx, just turned 4 months old. About 3 days ago [a Friday], she had her booster, and a rabies shots. [I have to brag: My dad took her for me, and she was absolutely PERFECT-not a peep!] Well, she was so-so active the rest of that day, and on Saturday she was her active, hyper self! Running, jumping, biting, being a turd, etc.
Saturday night, she napped with me on the couch [it was her bedtime, and I was watching tv], and then slept in her bed the rest of the night. Sunday, my boyfriend came home, and she started to act a little off beat-he was gone for about 4 days, and I could tell she was excited to see him.  But that morning, she slept ALOT. Normally, she's up at about 7, plays until about 11, naps for half hour to 45 mins, then plays til 4 and naps some more, then she's up and crazy til 10 [this is all on days that we're home all day-I do know that she plays in her box when home alone]. On Sunday, I think she was only playing for about 2-3 hours MAX the whole day. I woke her up often to play for about 10 minutes, but once I started to walk away, she's crawl back in bed and be sleepy. I know she's sleepy, because only at night or first thing in the morning is when she asks for a belly rub.
I've taken her on quite a few walks, and we did go on a pretty long walk last Wednesday night, but not since. Is it because the weather is getting colder? We keep the house pretty warm for her-that way she isn't shivering.
Also, she does submissively/exciteably urinate. It's submissive to me, even after I changed my tone of voice, and my mom ALWAYS uses an upbeat voice, and she does it to her too. I did, however, just find an article of yours about not bending over and such, which might help her...if she ever gets up to play again tonight! Usually I only let her approach me. [Other than this random submissive peeing, she is awesomely litterbox trained/house broken.] Just earlier today, she had her first accident in nearly 3 weeks, while we were playing-but I noticed her behavior to be submissive right when she did it. I have no idea as to why-I was all kinds of upbeat and cheerful!
Sorry to make it so long and slightly scattered...But I'm the only one that makes an effort to train her. The submissive thing I need a lot of help on-I've been doing my own positive obedience training which she has taken AWESOMELY to [Sit, Stay, Lay down, Shake, Speak, Tell me a story, Back up, all within a month and she uses them nearly daily].
=[ So Binx and myself [and my boyfriend] ask for help!

Answer
It could be all of the above, that's a lot going on: double shots, weather change, big exercise, probably teething, growing as fast as she is ever going to grow etc.

If she had a reaction to her inoculation it typically includes drooling and a big red bump at the site. Maybe spread them out next time instead of doing both on the same day.

She is only 4 months old so submissive urination coupled with not full muscle control over her bladder and maybe just not quite there housetrained will dissipate as her skill and her age move away from both those things. Try not to make a big deal about the submissive urination and it should fade.

Sounds to me like you are doing lots of stuff right, she is very young so make sure to keep all training happy and successful!