"i had my first shot when i was 18, i had heavy bleeding and weight gain for the whole 3 months. my doctor told me that was normal that when i got the second shot it would stop or lighten up. well i got my second shot and it still wasn&#039;t stopping. so for a total of 6 months i was bleeding heavily. by then end of it i found out i was pregnant and had a miscarriage. i had only been about a month or two along. so just be careful and if you aren&#039;t using anything else but the shot, still pay attention to your body, and take pregnancy tests. just to make sure. because i got pregnant a month after i took the second shot."