There are varying opinions (as usual ) Some believe it is better to wait to allow a normal cycle to recommence. Others believe you can try as soon as you are emotionally ready. Some say it increases the risk of miscarriage to fall pregnant immediately. Others say there is no difference whatsoever. Some sat to wait 1/3/6 months

Unfortunately, as with any pregnancy, there are no guarantees You may fall pregnant immediately and have a normal, uncomplicated pregnancy or you may not. It is impossible to say. At 15 weeks, you are a second trimester loss which should be discussed with your OB. There may need to be additional tests to determine if there is a why to your loss which may impact on your next pregnancy. This may make you consider alternatives of when to TTC.