Well, the chance of seeing anything after an abort is very slim.... if you don't see it right after, and I mean within a few hours at most......you would most likely not see anything. I would think that she would not be making that sort of discharge if she was not close to calving now though....
I would have been walking the pasture with seeing that kind of discharge and her acting a little off.....but then I drive most all my pastures when I have cattle due, every day.... right now I cannot walk them due to my knees... but I will drive them, and get out and walk some if I suspect that someone may have calved in a certain area....I think you really need to do a very close scrutiny of the pasture if you don't get the vet out to confirm she is still pregnant.
What is the status of the other heifer?
Honestly, I would get the vet and get them both checked.... most vets here do ultrasound for pregnancy checking... it is VERY ACCURATE... but a good vet that does palpations can give you a good idea of how far along as they are... up to 5-6 months.....when they can say yeah, they are 5 or 6 or pretty far along as the fetus gets way down over the pelvic bones and it is harder to just be as accurate as to how far pregnant. In your case, you have 2 definite "breeding times"... it would not be hard for a vet to say yes to the Oct breeding, or yes to the Feb breeding.....
This way you know what you are looking at time wise.
That is why we just rechecked a group of cows.... thinking they should have calved, and finding that there were several not pregnant.... as we suspected.... and got a better idea of the ones that were pregnant, when they are due....
It is well worth it to me to know what is what... our vet gets $100/hr.... not cheap... but cheap enough.... to not sit and worry myself sick....