Several side effect of lupride injection is constipation, back pain, vaginal discharge, and due to constipation bloating of stomach is also possible. But this all can be controlled now since you are not on same medication. This control can be done by improving your life style and doing certain changes like having healthy balance diet, maintaining timing for break fast, lunch and dinner. Keeping break fast good lunch average and dinner minimum that too at or before 8:00pm, also avoid spicy food. Have fruits regularly. Keep tea and coffee minimum, keep fibre diet more in your meal. Do regular exercise like walking or jogging or cycling at least 25-30 minutes per day. Next your question is how to treat back pain: I suggest if your pain is only at back and not radiating to your legs as well there is no signs like numbness in leg and tingling sensation. Then it must be related to your spinal muscle weakness. And you need to take physiotherapy treatment after proper evaluation. As well follo spinal exercises regularly to improve strength and stamina of spinal muscles. You can also use hot or cold pack frequently at home to have some more pain relief. Also check your vitamins d and calcium level in body if it is low take a supplement for the same. Next question was on pregnancy: yes you can get pregnant if there is no further gynec issues. But during the pregnancy you will put up on weight and so that you may have more back pain. So discuss with your physio and do regular spinal exercises as well take advice on posture priorly only. Another thing to answer your headline question: Increase back pain, bloating of stomach is possible during pregnancy. I am sure this must be helpful to you. Take care