HCG level 120, 5th week after LMP. Min?

Hi, I have a 28 day cycle and I am supposed to get my date on 24th April, but now its delayed by 5 days. I had been taking the pregnancy urine test for past 3 days and the kit showed no line within the 10 min window. But the pink line showed up after 30 minutes. As it is outside the window I did not consider it. But this happened thrice, so I took a beta HCG test and the level of HCG detected is 120. So I would like to know is this level of HCG bad in the 5th week(after my last LMP). I ovaluated on 7th April (I know the date because I got the follicular monitoring done this cycle). My doc suspects it to be a chemical pregnancy, and recommended the beta hcg test after 48 hours. Also though the HCG level is 120 as per beta hcg report, why the urine test fails to a show a positive line in the stipulated timeframe of 5-10 min ? Putting all this together I am really not sure what is happening.