Af is late...

So I’m normally really regular with af coming 14/15 days after ovulation. I am three days late at the moment. I had quite intense cramping on my left side at 10 and 11 dpo which was something I have never felt before. I have been certain af is coming as I have had cramps on and off for the last week. I have adenomyosis so this is normal for me before af arrives. I have felt slightly nauseous at times and have had itchy nipples although this has calmed down in the last few days. I am away on a school trip (i am a teacher!!) and purposefully didn’t bring a test because I was sure I was going to come on at some point in the week. I know it’s still early days but something just feels different this month (this is month 16). Am I just getting my hopes up? X