If you traveled to the future, but not too far away, met your future self and killed them before they had a chance to conceive a child, would this provide a contradiction? Whether or not you will conceive a child in the future is indeterminable unless you have traveled far enough into the future to find out. You would then have to travel backwards to tell yourself about the past or carry out the murder yourself, but you traveled to the past and the same contradictions stated previously occurred. There doesn't appear to be any way to confirm that you will conceive a child in the future without traveling backwards. However, the logical possibility of time travel is still far away