I think I’m pregnant

I’m like 5 weeks late and I’m irregular anyway so this is some what normal.

However, I’ve been having pregnancy like symptoms such as nausea, diarrhoea/constipation, being sick, headaches and cramps in the lower abdomen. I did a test when I was about a week or 2 late but was negative and have read that this could just mean I’ve done it too early.

I don’t know if it is worth buying and doing another one or just to wait until I come on my period?

Help please