Hi I Need A Small Bit Of Advice I Am

hi i need a small bit of advice i am a very healthy 26 year old trying for a baby with my partner. i am never late for my period my cycle is always 21-23 days periods lasting 2-3 days miss 12-14 hours then a tiny bleed again i haven't really felt my self over past 4 days so i decided to do a pregnancy test using the first morning urine and it came back with a very faint line i read the leaflet that came in the box and it said a faint line means positive however with it being faint i decided to leave it till the following morning and test again only i used a different type of test and it came back negative i do not no what to believe i spoken to my doctor and she said there is no chance you can get a false faint lined positive pregnancy test but it still doesn't explain the negative test i tested again this morning and it was negative again is there any chance i am pregnant? my last period was the 3rd of auguest i bleed very light and i only bleed on and off but stopped by 5th and then had a very small bleed on the 8th i am very much confused