In the first trimester of your pregnancy you need to take care; so you cannot actually begin exercising to keep fit . You can however do some simple stretches that will release your joints and loosen you up.
Sit cross legged; keep your knees on pillows, as that may be more comfortable. Now slowly do some neck rotations. Close your eyes and concentrate on your breadth. Next in the same position do what is called the shoulder shrug. Lift and drop your shoulders for twenty counts.
Now keep your hands behind your head and stretch on one side; pulling one elbow with the other arm. This is loosening your upper arm joints and muscles. For your next exercise keep your right arm on your left knee and gently twist your torso and your neck. Stay in that pose for a few seconds and repeat the same on the other side.
Now get near a wall and lie down in such a way that your buttocks are touching the wall.Lift your legs against the wall and keep them straight up. Keep flexing your toes. Now using the wall for support drag your feet so that the soles of your feet touch each other. You may find this a little difficult to do as you may not be that flexible. Stretch a little more everyday till you eventually get it. Just keep concentrating on your breadth.
Before you complete all these exercises sit cross legged and keep your hands in your lap; this is a bit of relaxation and meditation. Be aware of all the sounds around and stay like that for seven to eight minutes. Now lift your arms up towards the ceiling and gently bring it down.
Do this five to six times and then slowly get up. Now stand for the next set of exercises. Keep your legs slightly apart and bend your knees slightly. Keep your arms outstretched beside you and bring them forward so that you join your palms. Repeat this ten times.
Now you can try and do some side lunges while you are standing. Do not do more than fifteen as you are pregnant and only need to loosen up not lose weight.