Sore breasts 1DPO and positive HPT??

So I got a positive opk on the morning of the 9th we did the BD twice since then and tonight on the 10th when I was getting dressed noticed that my nipples are really sore.. not the whole boob just the nipple area... I don't normally get sore breasts even before a period so it's strange to me. Just wondering if anyone has heard of it or had it happen to them before on 1DPO and gotten a positive hpt later.