4 days late and 2 BFN

So My husband and I have been trying to conceive since September. We used preseed this cycle, and my period was due on Thursday and so far it's not turned up. So I'm super excited and I test on Friday and BFN. I'm so disappointed but I also feel like I'm not out of the game yet... maybe it's just too early. So I check again today and another BFN! I've no idea what to do.... or if There is even anything I can do. Patience is not my strong point and ive now convinced myself maybe I'm pregnant but I'm using cheap tests and maybe it's still too early. Does anyone think it's the tests? Or do you think I'm out this month. My heart is full of hope but my head says I'm heading down the heartbreak route and that my period is just late. I've not had any other symptoms other than my missing period.... all suggestions or advice welcome !!!