Question? Need advice

This month my period was supposed to start the 23 til the 26. I'm always regular and get it at the end of each month. This month I haven't. The 21, I used the bathroom and spotted only once. Today the 29 I spotted only once. This never has happened to me. I've always had a heavy flow. I've been trying to get pregnant for 9 months already. I've been having sex throughout this month like crazy. Now i don't really think about sex. Could I be pregnant? Any advice ladies?