I'm worried could I be pregnant?

Me and my husband have used protection all the time during . The other night during and before the condom was placed on the he may have d me for a brief second. I'm worried about pre-***. I took a pregnancy test one day after my missed period and it was negative. I waited to see if I would get my period and still haven't and I am now four days overdue. I took another test and it was NEGATIVE but the line was faint not dark. I'm worried. We aren't in a position to have another child right now. What does a faint negative line mean? I did the test about midway through the day. I've had two negatives in a week one dark negative one faint negative. Could I be pregnant and if not why is my period late?