I am 17 days past transfer with very faint line.

Hello ladies. We had fresh transfer on 21 this month. I felt like i was pregnant from the next day past transfer but strongest cramping i got 9 days past egg retrieval. I assumed it would have implanted by 11 day past ovulation. I doubt it was past 12 and my line is very faint. Nothing like the strong positive i should have. Tested with another first response with same urine even lighter. Pulled out my first vew opks shows line as dark as control. Tested with another opk with sensitivity 35 nothing not a faint line. I doubt it is higher than 25 maybe even ten. And as I know when it was my retrieval and that they transfered day 5 blast I know i am not week behind. I am supposed to be 4 weeks tomorrow. It is 30th day of cycle tomorrow. I start to think it is chemical again. Even though i am still feeling very nauseous. Vomited yesterday. My last chemical at 17 past egg collection the line was as dark but at 13 day i started bleeding and line was still darker. I am absolutely confused. Nurses said that might not be chemical and to test tomorrow. They do not think this is the trigger in my system.Did someone achieve successful pregnancy with so faint positive results so late? I am not holding my breath but as they say hope dies last. This is my second ivf cycle first ended with chemical. Forgot to mention i am not spotting or bleeding and i keep feeling pregnant. Vomited yesterday and today so very nauseous. Have other symptoms too like weird low abdomen sensations but not like menstrual cramps. Is it a slow grower or on last leg? My private clinic in The UK do not do beta. Gp wont want to test me unless strong positive present so I am in the dark. Must test tomorrow. Any hope?