R+L=J v.32

[SFDanny]

She need only be a single day 'ahead' - heck, she needn't even really be 'ahead' at all, since Brandon went to the wrong place.

But no disagreement in general about potential timeline and her being with Rhaegar 13 months or even more before Ned found her at ToJ.

The likelihood of her being with Rhaegar for 13 months or more is very small. Thirteen months or more from when she disappears to when Ned finds her is very probable, but Rhaegar is only with her probably close to half of that time.

We have no idea how long he 'waited' or even if he 'waited' at all.

Pregnancy might happen the first time you have unprotected sex. Or the 1000th time.

My wife and I got married ready and actively trying to start a family immediately, due to our ages, and it took 4 months to get pregnant. Thats almost exactly the amount of time you seem to be complaining about with Rhaegar and Lyanna.

Your real world reality is, most importantly, confirmed for Martin's fantasy setting when Catelyn tells Robb almost the same thing you point to - the first or the thousandth, one never really knows until it happens.