evaporation line or pregnant?

Hi, I am looking for some advice or opinions on faint lines on a pregnancy test.

I have irregular cycles, normally ranging from 35-50 days and im currenty on cd 34.

at the begining of last week I started to get really crampy and had pains in my breasts, i assumed i was or was due to ovulate so i started using my opk but up untill now i have not had a positive.

Out of curiosity I took a preg test and have done about 10 uptill now. I keep seeing a faint line but im not sure if it is actually a faint positive or if its a evaporation line or my eyes playing tricks.

The latets test i took was this morning and a faint line appeared before the 10 min mark and then it went darker and then light again as the test dried. I took a digital test yesterday and that was negative.

I am so confused now cos I still feel crampy (not period cramps) and also still have sore breasts.

I dont really want to take any more test yet as i feel i may be wasting my money.

any ideas anyone?

ps, i also seen a small amount of brown blood this morning, it was about the size of a raindrop and have had no bleeding since.