Hi
I found a really cheap test that seemed to work for me. They're called "Assurance Plus: Early Pregnancy Test" made by Integrated Sciences in Sydney in Wentworth phone 1800 252 204. They are in stream ones - and 2 of them were ony $13 (have caps).

I used one at 7 days -ve. Then at 10 days +ve. On day 13 I used a Clear Blue and it confirmed it. BFP on Day 14 confirmed pregnancy HCG 404 and P4101. Doctor says all's good.

Good luck
Cia