1 pos test 1 i cant tell?

I have a question about pregnancy tests. Heres whats going on... My period was to today oct 10th and anxious to find out if i was pg i took a dollar store test (50 miu from what i read online) right away in the morning and it was a BFN. Then when i got off of work i went and pick up a two pack of the Answer early results test(25 miu or less from what i read) and took one. I got a BFP! It showed up within less than a min and a half. the line was very faint but definitely there! Then anxious to see if id get another BFP i took the 2nd one from the pack about 2 hrs later. and with this one you REALLY have to strain to see the line. is it just cuz of the fact that the hcg in my urine was so diluted since i had peed earlier and then drank a big gl of juice? I just dont wanna get excited too soon. any thought are appreciated. also.. What can you tell me about that brand of pregnancy tests.