Suspect that your bovine (bull, cow) is pregnant. Well, there's only one way to be sure. Put on a plastic glove and insert your hand into the rectum, with your fingers together. See how to find out if your cattle is pregnant with help of this video tutorial.
Press down on the rectum and sweep the pelvis to find the reproductive tract. Upon finding the reproductive tract, your target is to find the cervix. The cervix will be a rope-like structure, like a chicken neck, that can be grabbed and held. If you lift up and feel weight, one would suspect that there could be a pregnancy present. To check for sure, follow the cervix down over the pelvic brim, and follow the reproductive tract down over to where you can feel a large fluid-like structure. This would be the uterine horns, filled with fluid. Here you will find a positive sign of pregnancy.
This is a great educational video for veterinarian and farmers.