I had my last period on January 11th and then had sex on January 26th. It was a week after ovulation so I thought I couldn't be pregnant but then a few days my period was due my breasts were extremely sore. My period came on time and was heavy for a day but after that it slowed down. The blood was bright red when it first came but then lightened up. Could I be pregnant?

Any time you have sex at any point in your cycle you can become pregnant.