You must look out for these Early Signs of Pregnancy which are mentioned below to find out the physical status of your female dog/bitch:
1) Decreased appetite is usually one of the earliest signs that your bitch might be pregnant.
2) A sudden decrease in activity can indicate that your bitch is pregnant.
3) Nipple growth is a good indicator that your bitch's body is going through pregnancy changes. The nipples of an unbred female are usually quite small, and the area immediately beneath them will feel flat. However, once a pregnancy is in progress, breast material will develop beneath the nipples, which will also increase slightly in preparation for milk production.
4) Behavioral changes may also be noticed, with either an increase in affectionate behavior or an expressed desire to be left alone. As the pregnancy progresses, you will notice further changes.