Could I be pregnant?

Xiomara • I am 27 years old and my husband and I have two beautiful children. Our daughter is 8 and our son is 7. We are TTC baby #3.
My cycle is usually 29 days but now I'm at 38 and still no sign of a period coming. Could it be? I'm so scared to buy a test. It's been 7 months of trying. Please tell me what you think I should do.