Pregnancy symptoms and maybe testing too early???

So with my other pregnancies I was always constipated around the time I found out I was pregnant and that's when I knew fir sure I was pregnant. I don't know why I do this to myself but each time I'd buy the pink line pregnancy tests the day I'm due for my period maybe the day before. Each pregnancy I did this because they say up to 6 days sooner you can get a positive. But then each time they told me I wasn't pregnant and I'd be so disappointed. But then I'd wait till I was 2-3 days late and go buy a digital test that says "pregnant" or "not pregnant." Come to find out I was in fact pregnant. It didn't make sense to me why the pink line ones couldn't pick up the hcg yet the digitals could??? well my daughter is now 6 so it was quite some time ago so I'm not absolutely positive. Anyways, I'm due for my period today but I took the pink line test yesterday afternoon and then a pink line test this morning and both appeared negative to me. I've been experiencing constipation the last 5/6 days or so, face breaking out, tightening in stomach, gasiness. Normally my boobs start to hurt a week before my period but they haven't hurt at all?? I'm just wondering whether I should give in and buy a digital test in a couple days if I don't start my period?? I don't want to be dissapointed though. Anyone having these symptoms or experience getting a negative on the pink line tests only to find out they were pregnant a little later??