It very well could be that you are pregnant.
Yes, it is normal to see vatiation in your breast size throughout your entire menstrual cycles but especially around ovulation and menstruation. The breasts are not growing or shrinking, the ducts in the breasts are swelling due to the effect of hormones on the breasts.
First of all, no-one would be able to tell if they were only 3 weeks pregnant (this means a week after ovulation!) if your going off your ovulation, then yes it can feel spongy & swollen - the reason for the swelling is, increased blood flow, therefore your cervix would be blue also, which is very normal.
The breasts are how they are. During menstruation they can get swollen but a normal breast is never hard. If she has implant she needs to speak to her surgeon.
Yes, some women do get extremely sore breast premenstrually.
I have been told by a breast cancer nurse that this is completely normal and due to an increased amount of estrogen. This can be exacerbated by being over weight.
Yes, it is very normal to get excited. You feel more mature and it means you are growing up.
Swollen feet, legs, arms everything is normal for pregnancy.
It is normal for your breasts to get larger as you grow.
Well take a pregnancy test to make sure, and it might just be a normal thing. so yeah, a pregnancy test sounds good.
Sore breasts may be an indication of hormonal changes such as ovulation, menstruation or pregnancy - not normal, but can occur if there are hormonal imbalances. Breast soreness can also be due to breast growth, especially in your teens, also if you're wearing a bra that is too small or that doesn't give your breasts enough support this can also cause breast soreness.
It is not that they are getting smaller, it is that the breasts are going back to their normal size. Birth control can sometimes make the breasts swell, just like right before your period. They will not be any smaller then before birth control.