Please help me? :( worried

Brandi-lea • Khaleesi-May Dizney Van Vliet - my precious daughter born on 23.6.15 👶🏼🌸
I am 15dpo today, making me 2 days late for AF. I tested with a frer this morning with fmu and I had an extremely faint positive. So faint that although you can see it, I have never seen a frer this faint. I'm worried because surely by 15dpo it should be darker.
​A few cycles ago I had a chemical pregnancy, I have been trying for a baby for over a year and it's becoming extremely disheartening. 
​I got a very strong bfp this cycle at 7dpo, but after using a lot of other brands that were ALL negative I realised this must have been a faulty tests.
​I continued to test everyday from 8dpo to 12dpo. Finally, I got a faint line at 12dpo. I got excited so ordered more tests. I have about 5 different brands of tests. I tested again at 14dpo (yesterday) the day of my missed period and got faint lines again.
​I had frers delivered to me today (15dpo) and tested with fmu. I got a faint line instantly but like I say it's so very very faint. I have had a lot of people on glow say that they can see it but they can't help with answers as to whether it's good or not that it's so ain't at 15dpo. 
​I tested again afterwards with an asdas 25miu test, two different brands of dip strips, a cassanovum pink hpt test and also a cassanovum midstream. Faint lines on all of them too. 
​Below I am going to post pictures of my tests with the dpo. If anyone could tell me if it looks like this could be a chemical pregnancy or not that would be great. I'm feeling very stressed that I don't know what's going on. 
  
This was the faint line I got at 12dpo ​ 
​I got these at 14dpo  
And I got this today (15dpo) with a frer 
​If anyone could help I would be so grateful. Thank you