Hello. Well, unfortunately, if you had unprotected sex last month and your period is late, you really need to just take a test to find out. :>)) A dollar store test or urine test from the grocery will give you your answer. Use first mornings urine if possible and follow the instructions exactly. I will tell you that women are late ALL the time and it can be out of nowhere. Yes, changes in routine including exercise routines can make us late. As can stress, illness, trauma, weight gain or loss or having a slow or fast thyroid. All can impact our cycle making our period come later than usual. So, get the home pregnancy test (they are cheap and pretty reliable) and do that. If not, you can wait to see if your period comes and if it doesn't in a full week, take another test. By then you would get a positive most likely if pregnant. If it still doesn't show, consider seeing your ob/gyn. They can do some blood work to see if hormones are funky. But most women ARE late from time to time. good luck