I ovulated on Christmas Eve...... We did have sex that evening. My period always comes 12 days after ovulating. And yesterday it did not come. Iv been cramping since Monday and having white mucus..... I bought boots own brand tests which are from 25miu so I really need a more sensitive one I think? But the boots shop beside me only sells those ones so would have to go Into town...... Or would it generally show by now at 13dpo on a 25miu???