Light red blood

Maggie
Hi lady's, I have been feeling very swore and a lot of pressure down there. Even when I walk it aches like I did two hours of leg day. In the morning my pannie liner was fine. Then this afternoon i peed and changed my pannie liner and I saw light red blood on my pannie liner it wasn't much but it was definitely there. First time I have seen it. I just turned 32 weeks. Any one knows what this can be?