Name that book!- white woman confined to period hut

Read it a few years ago, but I remember it felt like an older book, 80's, 90's maybe, not sure if it is a period piece.

The biggest thing I remember was that the cover was a stereotypical romance book cover. White woman on the cover with possibly a flowing blue/light blue/mint/pink dress. Main love interest, a man is also on the cover, he may not be white or possibly mixed race.The background is possibly blue, maybe nature- like a waterfall/river and the characters may be on grass.

I vividly remember reading that when this woman got her period, she had to be secluded into a period hut with other women until it was over. I think the woman was well off financially, but for some reason or another, she left her husband because he was cruel towards her and is traveling across the country with this man who is supposed to protect her. I think this man is supposed to take her back to her own family, where she will be safe from her husbands family. She soon sleeps with and becomes romantically involved with this man. She may also become pregnant though I am not sure