Could I be pregnant? Please help!

My boyfriend and I had sex for the first time last weekend. We decided to just do oral on each other since I was a bit scared.

I was on my first day of period on our date so he just fingered me and I went down on him, but then I tried to insert his dick into me. It didn’t go in at all though because I’m very tight and he is pretty big.

I’m just wondering, could I be pregnant?

1.I was on my period at the time.

2.His dick didn’t have cum on it when I tried to insert it

3.It did not go in, maybe just a little bit of the head but I couldn’t get the whole thing in so I just grinded on it.

4.He didn’t have precum

What are some of the earliest signs of pregnancy without having to test it?

Please help!