I don't think there is a biological link to red lips--> ovulation. It's more symbolic, in that invokes the image of a reddish, swollen vag--pre-historical signals that has been carried down from early primates.
This is why the prostitutes in Pompeii invented lipstick--to convey that image of virility. I think it's more of a visual symbol, not anything linked to a real biological connection.
as for the forehead, I'm willing to go with that as there are known links with hormone balances while the fetus is gestating, that lead to tracable lengths of your digits--shorter second toe vs longer 2nd toe (compared to big toe), length of forefinger, etc. Definitely biological stuff there--but I think it's just hormonal; the myths that such signals are linked to fertility are well, simply myths.