Not TTC but am I pregnant?

Kayla • 28. Wife. Mom. Type 1 diabetic.

The past few nights I have been waking up in the night with nausea & it has continued on into the morning & sometimes throughout the day. I never feel like I am actually going to get sick. It's just the constant nausea. I am freaked out because this is the same way I felt with my first pregnancy. I ovulated the week of august 22nd & had sex on one of my highest ovulation days. I am on birth control & we do the pull out method. I then had a very light period on & off September 9th-14th. I always have very heavy periods & this one was very light & would be on & off for a few days so I am wondering if it could be implantation bleeding? Could I possibly be pregnant? I was extremely lucky with my first pregnancy & got pregnant after our first month TTC so I don't know a lot about ovulation/implantation timelines & what not so sorry if this is a dumb question!

Also I just switched from a birth control that only allows me to have 4 a year to a monthly birth control so my periods have been pretty irregular which is why I had two last month. So I'm not really sure when my regular period should be 🤷🏻‍♀️