Possible pregnancy???

Morning ladies! So my period was due to start on Friday which it did(👎🏼) but it ended Sunday sometime which is extremely unusual for me. My periods are always 6-7 days long never shorter. Today I’m feeling nauseous as all get out, really tired, and have some slight back pain. I haven’t tested yet and I know you can have some light bleeding early on. But this was red like a period, not extremely heavy but like a normal period. Is there a possibility of having this and still being pregnant?