Was excited but now... Not sure!

I took an Answer pregnancy test two days ago at 17dpo- and it was positive. Took a digital Clearblue later that day and got a Pregnant 1-2 weeks. Was actually beginning to believe it- but then took a e.p.t. Test yesterday and only got a very faint line if any at all. Don't know what to believe- please help. Is this normal because of test sensitivitity?