I was so ridiculously exhausted. I otherwise felt completely normal but I was so tired that I was ready for bed 2 hours after getting up from a 9 hour sleep for a few days in a row.
I started to think something must be up and despite being on the pill (taken with army precision!) and only having one Fallopian tube the word pregnant popped into my head and I couldn't shake it until I got a test. Big fat positive came up and I think it was 2 days before my period was due.