Anyone else experience this?

[sjcaddy]

I'm currently not on any BC I had a regular period from the 20th Dec - 25th Dec I had intercourse with my partner multiple times after my period then I started to get stomach cramps and pain on the side it felt as if my period was coming but couldn't be because I just had it.

Now on the 9th of Jan I got pinkish discharge for a day and then blood it was light nothing heavy but this was only for 4 days really bad period cramps keep in mind I NEVER get period cramps ever so this was unusual for me - after that period stopped I continued to have random lower back pain, stomach cramps and also chest pain for a second also aching breast (not too sensitive) my urine has a strong smell (I've been doctors to see if it was UTI or bladder infection they've found nothing) I've taken pregnancy tests and they've all come back negative..

Has anyone experienced this and found out they were pregnant later on..