First Signs Of Pregnancy

Me and my husband have been trying for a baby and I am wondering what the first signs of pregnancy are. How soon do they occur? Please help.

my sisters yorkie has just had her first season, she homed her with my brother during this time, when her season had finished we brought her home but my mums yorkie locked onto her, she was only one day clear from her season, this was one week ago, we contacted the vets and they will be scanning her at the end of the month… her nipples are swollen is this from her season or first signs of pregnancy??

I have a 6 1/2 month old kitten and she slipped outside about a month ago and we had a male cat that wasn’t fixed. She has gained weight around her stomach area. We thought that she was just getting fat but she hasn’t increased her eating. She doesn’t have worms, we already checked for that. Can You Help Me? Thanks!!
Also, She couldn’t have eaten any food because we are the only ones on our block with a cat. She can’t even climb the walls that fast because she is so tiny.

Her teats aren’t big but feel like they are filling with milk.
Please Don’t Waste my time with your stupid answers.

Hey
my sow has been with the boar for around 18 days ( from 30/August/2008 ), so what are the first signs of pregnancy, and when do they occur?

My last period was 17th August which makes me 10 days late today. I took a HPT on Saturday but misread the instructions and put it in the test stick upside down, by the time I’d realised and corrected it I’d got a negative. I’m feeling slightly nauseous and my boobs are sore (this is not all the time, it comes and goes). Is it normal to experience signs at about 5 - 6 weeks or are they later on? Thanks in advance for any replies.

What do you feel first or what are the type of changes you go through?